{"title":"MerCruiser 7.4L 454 MAG V-8 Sterndrive — 0B721206 THRU 0D805068","description":"\u003cdiv class=\"model-catalog\"\u003e\n\u003cp\u003e\u003ca href=\"\/collections\/mercruiser-7-4l-454-cid-v8-gm-sterndrive\"\u003eBack to MerCruiser 7.4L 454 CID V8 GM Sterndrive\u003c\/a\u003e\u003c\/p\u003e\n\u003cp\u003eSelect a model, production range or part section to narrow your search.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/collections\/mercruiser-7-4l-454-mag-v-8-sterndrive-0b721206-thru-0d805068-cylinder-block-and-camshaft\"\u003eMerCruiser 7.4L 454 MAG V-8 Sterndrive — 0B721206 THRU 0D805068 · CYLINDER BLOCK AND CAMSHAFT\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/collections\/mercruiser-7-4l-454-mag-v-8-sterndrive-0b721206-thru-0d805068-closed-cooling-muffler-kit\"\u003eMerCruiser 7.4L 454 MAG V-8 Sterndrive — 0B721206 THRU 0D805068 · Closed Cooling · Muffler Kit\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/collections\/mercruiser-7-4l-454-mag-v-8-sterndrive-0b721206-thru-0d805068-exhaust-manifold-and-exhaust-elbow-cast-iron-exhaust-elbow\"\u003eMerCruiser 7.4L 454 MAG V-8 Sterndrive — 0B721206 THRU 0D805068 · EXHAUST MANIFOLD AND EXHAUST ELBOW -CAST IRON EXHAUST ELBOW\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/collections\/mercruiser-7-4l-454-mag-v-8-sterndrive-0b721206-thru-0d805068-exhaust-manifold-and-exhaust-elbow-stainless-steel\"\u003eMerCruiser 7.4L 454 MAG V-8 Sterndrive — 0B721206 THRU 0D805068 · EXHAUST MANIFOLD AND EXHAUST ELBOW(STAINLESS STEEL)\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/collections\/mercruiser-7-4l-454-mag-v-8-sterndrive-0b721206-thru-0d805068-muffler-kit\"\u003eMerCruiser 7.4L 454 MAG V-8 Sterndrive — 0B721206 THRU 0D805068 · Muffler Kit\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/collections\/mercruiser-7-4l-454-mag-v-8-sterndrive-0b721206-thru-0d805068-raw-water-cooling\"\u003eMerCruiser 7.4L 454 MAG V-8 Sterndrive — 0B721206 THRU 0D805068 · Raw Water Cooling\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eMatch the model and any listed year, serial number and configuration before choosing a part.\u003c\/p\u003e\n\u003c\/div\u003e","products":[{"product_id":"27-8637251-closed-riser-gasket-set-2-pcs-for-mercruiser-v6-v8","title":"27-8637251 Closed Riser Gasket Set (2 Pcs) for MerCruiser V6 \u0026 V8","description":"\u003cdiv style=\"width:100%;max-width:960px;margin:0 auto;box-sizing:border-box;font-family:Arial,Helvetica,sans-serif;font-size:16px;line-height:1.75;color:#293a35;background:#ffffff;overflow-wrap:anywhere;\"\u003e\n \u003csection style=\"padding:28px 24px;margin:0 0 40px;border-top:5px solid #234d40;background:#f5f3ec;box-sizing:border-box;\"\u003e\n \u003cp style=\"margin:0 0 14px;color:#456052;font-size:12px;line-height:1.6;font-weight:700;letter-spacing:1.4px;text-transform:uppercase;\"\u003eSERDAMARINE \/ MARINE EXHAUST PARTS\u003c\/p\u003e\n \u003ch2 style=\"margin:0 0 18px;color:#203e32;font-family:Georgia,Times,serif;font-size:clamp(25px,4vw,34px);font-weight:400;line-height:1.25;\"\u003eExhaust Manifold Elbow Riser Gasket Set (2 Pieces) — Closed \/ Block-Off Cooling Configuration\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eThis two-piece exhaust manifold-to-elbow\/riser gasket set (referencing MerCruiser 27-8637251) is designed for specified MerCruiser GM V6 and V8 stern drive and inboard engines with center-riser exhaust manifolds and closed (fresh water) cooling systems. It applies to wet-joint center-riser arrangements from 1981 or 1983 depending on engine family, as well as GM V6 and V8 Small Block Dry Joint \"Alternative\" systems (0M serial numbers and up); it is not the open-flow or restricted-flow gasket version.\u003c\/p\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eConfiguration \u0026amp; Specifications\u003c\/h2\u003e\n \u003ctable style=\"width:100%;table-layout:fixed;border-collapse:collapse;text-align:left;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eJoint Position\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eExhaust manifold to elbow \/ riser (center-exit \/ center-riser manifold configuration)\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eFlow \/ Cooling Configuration\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eClosed (block-off) configuration for MerCruiser closed \/ fresh water cooling systems\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eExhaust Joint Compatibility\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eConventional Wet Joint center-riser systems and GM V6 \/ V8 Small Block Dry Joint \"Alternative\" replacement systems\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003c\/tbody\u003e\n \u003c\/table\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eEngine Applications\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eApplies to MerCruiser GM-based V6 and V8 stern drive (rear transmission) and inboard engines equipped with center-exit exhaust manifolds and the MerCruiser closed (fresh water) cooling system. Match the engine family, serial number range, cooling-system gasket position, and whether the installed exhaust is a conventional wet-joint center-riser or a Dry Joint \"Alternative\" system before ordering.\u003c\/p\u003e\n \u003cul style=\"list-style:none;margin:0;padding:0;\"\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMerCruiser Model 175–205 (GM V6, 229 \/ 262 CID)\u003c\/strong\u003e — Years: 1983 to 0M serial numbers. Exhaust configuration: Center Riser, Wet Joint. Cooling configuration: Closed (Fresh Water Cooling).\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n \u003c\/li\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMerCruiser Model 200–320 (GM V8 Small Block, 305 \/ 350 \/ 377 CID)\u003c\/strong\u003e — Years: 1983 to 0M serial numbers. Exhaust configuration: Center Riser, Wet Joint. Cooling configuration: Closed (Fresh Water Cooling).\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n \u003c\/li\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMerCruiser Model 330–370 (GM V8 Big Block, 454 \/ 502 CID)\u003c\/strong\u003e — Years: 1981 and up. Exhaust configuration: Center Riser, Wet Joint. Cooling configuration: Closed (Fresh Water Cooling).\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n \u003c\/li\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMerCruiser GM V6 \/ V8 Small Block — Dry Joint \"Alternative\" System\u003c\/strong\u003e — Serial numbers: 0M and up. Exhaust configuration: Center Riser, Dry Joint \"Alternative\" replacement system using the specified fresh-water-cooling closed gasket position.\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n \u003c\/li\u003e\n \u003c\/ul\u003e\n \u003cdiv style=\"margin:18px 0 0;padding:14px 16px;border-left:3px solid #8c622b;background:#faf5e9;color:#59421f;\"\u003e\n \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eNot Suitable For\u003c\/h3\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003e\u003cstrong\u003eOpen-flow or restricted-flow joint positions:\u003c\/strong\u003e This is the closed (block-off) gasket version for fresh water cooling; do not install in positions requiring open\/full-flow or restrictor water-passage gaskets.\u003c\/p\u003e\n \u003cp style=\"margin:0;\"\u003e\u003cstrong\u003eStandard OEM Dry Joint systems outside the \"Alternative\" configuration:\u003c\/strong\u003e Not a universal fit for every OEM dry-joint exhaust system. Do not select this gasket solely because an engine has a dry-joint exhaust manifold.\u003c\/p\u003e\n \u003c\/div\u003e\n \u003ch3 style=\"font-size:17px;margin:20px 0 10px;color:#143b31;\"\u003eAdditional model-specific applications\u003c\/h3\u003e\n\u003cul style=\"padding-left:20px;line-height:1.7;\"\u003e\n\u003cli\u003eMerCruiser MODEL 175-205 — GM V6, 229 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; Year \/ serial number condition “1983 - 0M SN#’s.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 175-205 — GM V6, 262 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; Year \/ serial number condition “1983 - 0M SN#’s.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 200-320 — GM V8 Small Block, 305 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; Year \/ serial number condition “1983 - 0M SN#’s.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 200-320 — GM V8 Small Block, 350 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; Year \/ serial number condition “1983 - 0M SN#’s.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 200-320 — GM V8 Small Block, 377 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; Year \/ serial number condition “1983 - 0M SN#’s.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 330-370 — GM V8 Big Block, 454 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; from 1981 onward,\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 330-370 — GM V8 Big Block, 502 CID, Wet Joint, Center Riser, Closed \/ Fresh Water Cooling; from 1981 onward,\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM V6 — Dry Joint “Alternative”, Fresh Water Cooling gasket position; serial condition “0M SN#’s \u0026amp; UP.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM V8 Small Block — Dry Joint “Alternative”, Fresh Water Cooling gasket position; serial condition “0M SN#’s \u0026amp; UP.”\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM-manufactured V6 inboard engines with center-exit exhaust manifolds and MerCruiser closed cooling.\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM-manufactured V8 inboard engines with center-exit exhaust manifolds and MerCruiser closed cooling.\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM-manufactured V6, application described as “rear transmissions,” with center-exit exhaust manifolds and MerCruiser closed cooling.\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM-manufactured V8, application described as “rear transmissions,” with center-exit exhaust manifolds and MerCruiser closed cooling.\u003c\/li\u003e\n\u003c\/ul\u003e\u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eReference Numbers\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eThe numbers below are provided for part identification and cross-reference only; they do not imply manufacturer identity or guaranteed interchangeability across different cooling configurations.\u003c\/p\u003e\n \u003ctable style=\"width:100%;table-layout:fixed;border-collapse:collapse;text-align:left;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eMerCruiser Stern \/ Out Drive\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e8637251, 27-8637251, 863725, 27-863725, 860231, 27-860231, 41811, 27-41811, 87918, 87918A1\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eMercury Mariner\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e27-863725, 27-860231, 27-41811\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eOMC\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e0502988, 0508715\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eSierra\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e18-0672, 18-0672-9\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eGLM\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e30220\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eMallory\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e9-61422\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eOther Reference Numbers\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e8503-GB, MC-47-27-41811\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003c\/tbody\u003e\n \u003c\/table\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eSupplied Parts\u003c\/h2\u003e\n \u003cul style=\"margin:0;padding-left:22px;\"\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003e2 × Exhaust Manifold Elbow \/ Riser Gasket (Closed \/ Fresh Water Cooling configuration)\u003c\/li\u003e\n \u003c\/ul\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eService \u0026amp; Installation Notes\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eGeneral service guidance only. Use the service manual for your exact engine and exhaust configuration.\u003c\/p\u003e\n \u003col style=\"margin:0;padding-left:22px;list-style-type:decimal;\"\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eShut off the engine, allow the exhaust system to cool completely, and disconnect the battery or disable ignition to prevent accidental starting.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eDrain the cooling passages in the exhaust manifold and elbow\/riser according to the engine service manual before loosening joint fasteners, and support heavy exhaust components during removal.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eRemove all old gasket material and inspect both the manifold and elbow\/riser mating surfaces for flatness, corrosion, or pitting while protecting the sealing surfaces from gouges.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eVerify that the closed (block-off) gasket matches the required cooling circuit position for your closed-cooling system before reassembling and tightening fasteners to the factory specification.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eAfter installation, run the engine with proper cooling water supply and inspect the manifold-to-riser joint for coolant, water, or exhaust leaks; stop the engine immediately and inspect if any leakage or abnormal temperature occurs.\u003c\/li\u003e\n \u003c\/ol\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;padding:24px;border-top:1px solid #bdc9c0;border-bottom:1px solid #bdc9c0;background:#f5f3ec;box-sizing:border-box;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eThe Serdamarine Approach\u003c\/h2\u003e\n \u003cp style=\"margin:0;\"\u003eExhaust parts need a configuration match. Serdamarine focuses on marine exhaust manifolds and their related service parts. Application details, connection requirements and public reference numbers are presented together to support part selection.\u003c\/p\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eQuestions Before Replacement\u003c\/h2\u003e\n \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eCan this gasket be used on open-flow or restricted-flow manifold-to-elbow joints?\u003c\/h3\u003e\n \u003cp style=\"margin:0;\"\u003eNo. This gasket is the closed (block-off) version for specified MerCruiser closed (fresh water) cooling applications. Open-flow and restricted-flow gaskets have different water-passage cutouts and are identified under separate part numbers.\u003c\/p\u003e\n \u003c\/div\u003e\n \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eDoes this fit all MerCruiser Dry Joint exhaust manifolds?\u003c\/h3\u003e\n \u003cp style=\"margin:0;\"\u003eNo. For dry-joint systems, this gasket applies only to the GM V6 and V8 Small Block Dry Joint \"Alternative\" replacement system (0M serial numbers and up) where this specific fresh-water-cooling closed gasket is required. It is not a universal fit for original OEM dry-joint manifolds.\u003c\/p\u003e\n \u003c\/div\u003e\n \u003c\/section\u003e\n\u003c\/div\u003e","brand":"Serdamarine","offers":[{"title":"Default Title","offer_id":45171576307763,"sku":"23GT297*2","price":16.8,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0699\/2930\/4115\/files\/marine-exhaust-part-28aaf6cea101517e.png?v=1792750277"},{"product_id":"27-863726-full-flow-exhaust-elbow-gasket-2-pack-for-mercruiser-v6-v8","title":"27-863726 Full-Flow Exhaust Elbow Gasket (2-Pack) for MerCruiser V6 V8","description":"\u003cdiv style=\"width:100%;max-width:960px;margin:0 auto;box-sizing:border-box;font-family:Arial,Helvetica,sans-serif;font-size:16px;line-height:1.75;color:#293a35;background:#ffffff;overflow-wrap:anywhere;\"\u003e\n \u003csection style=\"padding:28px 24px;margin:0 0 40px;border-top:5px solid #234d40;background:#f5f3ec;box-sizing:border-box;\"\u003e\n \u003cp style=\"margin:0 0 14px;color:#456052;font-size:12px;line-height:1.6;font-weight:700;letter-spacing:1.4px;text-transform:uppercase;\"\u003eSERDAMARINE \/ MARINE EXHAUST PARTS\u003c\/p\u003e\n \u003ch2 style=\"margin:0 0 18px;color:#203e32;font-family:Georgia,Times,serif;font-size:clamp(25px,4vw,34px);font-weight:400;line-height:1.25;\"\u003eFull-Flow Exhaust Elbow Gasket Pack (2 Pieces) for MerCruiser Wet-Joint and Dry-Joint Alternative Connections\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eThis two-piece full-flow (open) gasket pack seals the exhaust manifold, elbow, and spacer connections on specified MerCruiser GM V6, V8 small-block, and V8 big-block applications, referenced to MerCruiser 27-863726. It fits listed wet-joint exhaust assemblies within their original year and serial-number limits, as well as GM V6 and V8 small-block engines (0M serial numbers and up) equipped with a Dry Joint “Alternative” replacement system.\u003c\/p\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eConfiguration \u0026amp; Specifications\u003c\/h2\u003e\n \u003ctable style=\"width:100%;table-layout:fixed;border-collapse:collapse;text-align:left;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eWater-Passage Configuration\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eFull Flow (open center-riser configuration)\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eConnection Position\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eExhaust manifold, elbow, and spacer joint\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eJoint Compatibility\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eSpecified Wet Joint systems; GM V6\/V8 small-block Dry Joint “Alternative” wet-joint replacement systems (0M serial numbers \u0026amp; up)\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eProduct Scope\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eGasket pack only (not an exhaust manifold or elbow assembly; not a universal gasket for every wet-joint or dry-joint connection)\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003c\/tbody\u003e\n \u003c\/table\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eEngine Applications\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eThis full-flow gasket is used on the MerCruiser GM V6 and V8 manifold, elbow, and spacer applications below. Verify your engine serial-number range, joint style, and water-passage layout against the existing exhaust hardware; for 0M-and-up small-block engines, confirm that the Dry Joint “Alternative” wet-joint replacement system is installed.\u003c\/p\u003e\n \u003cul style=\"list-style:none;margin:0;padding:0;\"\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMerCruiser Model 175–205 (V6, GM 229 \/ 262 CID)\u003c\/strong\u003e — Years: 1983 through 0M serial numbers. Joint configuration: Wet Joint. Flow configuration: Full Flow (open). Position: Exhaust manifold, elbow, and spacer connection.\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n \u003c\/li\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMerCruiser Model 200–320 (V8 Small Block, GM 305 \/ 350 \/ 377 CID)\u003c\/strong\u003e — Years: 1983 through 0M serial numbers. Joint configuration: Wet Joint. Flow configuration: Full Flow (open). Position: Exhaust manifold, elbow, and spacer connection.\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n \u003c\/li\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMerCruiser Model 330–370 (V8 Big Block, GM 454 \/ 502 CID)\u003c\/strong\u003e — Years: 1981 \u0026amp; up. Joint configuration: Wet Joint. Flow configuration: Full Flow (open). Position: Exhaust manifold, elbow, and spacer connection.\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n \u003c\/li\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMerCruiser GM V6 \/ V8 Small Block — Dry Joint “Alternative” System\u003c\/strong\u003e — Serial range: 0M serial numbers \u0026amp; up. Joint configuration: Dry Joint “Alternative” wet-joint replacement system only. Flow configuration: Full Flow (open). Position: Exhaust manifold and spacer connection.\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n \u003c\/li\u003e\n \u003c\/ul\u003e\n\n \u003ch3 style=\"margin:18px 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eApplication Check Required\u003c\/h3\u003e\n \u003cul style=\"list-style:none;margin:0;padding:0;\"\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMercury Mariner \/ MerCruiser — 200 (DFI \/ EFI), 200 PRO XS, 225 (EFI \/ DFI), 225 SEAPRO, 250 (DFI \/ EFI), 3.0L\u003c\/strong\u003e — These model designations appear in supplemental product notes without joint-configuration or manifold\/spacer details. Match by OEM part number and physical gasket port layout before selecting for these engines.\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eConfirm application\u003c\/span\u003e\n \u003c\/li\u003e\n \u003c\/ul\u003e\n \u003ch3 style=\"font-size:17px;margin:20px 0 10px;color:#143b31;\"\u003eAdditional model-specific applications\u003c\/h3\u003e\n\u003cul style=\"padding-left:20px;line-height:1.7;\"\u003e\n\u003cli\u003eMerCruiser MODEL 175-205, GM V6, 229 CID, WET JOINT; 1983 — 0M SN#’s.\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 175-205, GM V6, 262 CID, WET JOINT; 1983 — 0M SN#’s.\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 200-320, GM V8 Small Block, 305 CID, WET JOINT; 1983 — 0M SN#’s.\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 200-320, GM V8 Small Block, 350 CID, WET JOINT; 1983 — 0M SN#’s.\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 200-320, GM V8 Small Block, 377 CID, WET JOINT; 1983 — 0M SN#’s.\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 330-370, GM V8 Big Block, 454 CID, WET JOINT; from 1981 onward, ending year not specified.\u003c\/li\u003e\n\u003cli\u003eMerCruiser MODEL 330-370, GM V8 Big Block, 502 CID, WET JOINT; from 1981 onward, ending year not specified.\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM V6, Dry Joint “Alternative” replacement system using wet-joint manifold and spacer connections; 0M SN#’s \u0026amp; UP.\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM V8 Small Block, Dry Joint “Alternative” replacement system using wet-joint manifold and spacer connections; 0M SN#’s \u0026amp; UP.\u003c\/li\u003e\n\u003c\/ul\u003e\u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eReference Numbers\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eThe numbers below are provided for part identification and cross-reference. They do not imply that this aftermarket gasket pack is manufactured by the referenced OEM brands, nor do they make different water-passage configurations interchangeable on the same engine.\u003c\/p\u003e\n \u003ctable style=\"width:100%;table-layout:fixed;border-collapse:collapse;text-align:left;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eMerCruiser Stern \/ Out Drive Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e27-863726, 27-818832, 27-860232, 27-871051, 27-87105, 27-87105-1\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eAdditional Short \/ Base Reference Numbers\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e863726, 818832, 860232, 871051, 87105\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eOMC Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e0508606\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eAftermarket Reference (Full Flow \/ Open)\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eGLM 32080, Mallory 9-61414, Sierra 18-2849-1, Sierra 18-2849-9-1\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eOther Flow Configurations (For Comparison Only — Not Interchangeable)\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eGLM 30240 (Restricted water-passage version); GLM 30220 (Closed \/ Block-off version)\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003c\/tbody\u003e\n \u003c\/table\u003e\n \u003cdiv style=\"margin:18px 0 0;padding:14px 16px;border-left:3px solid #8c622b;background:#faf5e9;color:#59421f;\"\u003e\n \u003cstrong\u003eConfiguration Distinction:\u003c\/strong\u003e GLM 32080 is the open (full-flow) center-riser gasket corresponding to this item. GLM 30240 (restricted) and GLM 30220 (closed) serve different water-routing setups on similar engine blocks and are not interchangeable with this full-flow gasket.\n \u003c\/div\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eSupplied Parts\u003c\/h2\u003e\n \u003cul style=\"margin:0;padding-left:22px;\"\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003e2 × Full-flow exhaust elbow \/ manifold \/ spacer gaskets\u003c\/li\u003e\n \u003c\/ul\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eService \u0026amp; Installation Notes\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eGeneral service guidance only. Use the service manual for your exact engine and exhaust configuration.\u003c\/p\u003e\n \u003col style=\"margin:0;padding-left:22px;list-style-type:decimal;\"\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eShut down the engine, disconnect the battery to prevent accidental cranking, and allow the exhaust manifolds, elbows, and spacers to cool completely before disassembly.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eSupport heavy exhaust elbows and spacers during removal so hardware and cast mating surfaces are not strained or damaged.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eClean old gasket material from the manifold, spacer, and elbow sealing faces, and inspect the surfaces for corrosion, pitting, or warpage without gouging the metal.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eCompare the new full-flow gasket ports directly against the removed gasket and the mating water passages. Do not substitute a full-flow (open) gasket in a joint that requires a restrictor or block-off gasket.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eReassemble and tighten fasteners according to the sequence and specifications in your engine service manual. After installation, inspect the exhaust and cooling joint for exhaust or water leaks under normal water supply; shut down immediately and inspect if any leakage or abnormal temperature occurs.\u003c\/li\u003e\n \u003c\/ol\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;padding:24px;border-top:1px solid #bdc9c0;border-bottom:1px solid #bdc9c0;background:#f5f3ec;box-sizing:border-box;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eThe Serdamarine Approach\u003c\/h2\u003e\n \u003cp style=\"margin:0;\"\u003eExhaust parts need a configuration match. Serdamarine focuses on marine exhaust manifolds and their related service parts. Application details, connection requirements and public reference numbers are presented together to support part selection.\u003c\/p\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eQuestions Before Replacement\u003c\/h2\u003e\n \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eHow does this gasket differ from GLM 30240 and GLM 30220?\u003c\/h3\u003e\n \u003cp style=\"margin:0;\"\u003eThis gasket corresponds to GLM 32080 (and MerCruiser 27-863726), which is the full-flow (open) center-riser gasket. GLM 30240 is the restricted water-passage version and GLM 30220 is the closed (block-off) version. Even when listed for the same GM V6 or V8 engine family, the three versions serve different cooling passage positions and cannot be used in place of one another.\u003c\/p\u003e\n \u003c\/div\u003e\n \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eDoes this gasket fit factory MerCruiser Dry-Joint manifolds?\u003c\/h3\u003e\n \u003cp style=\"margin:0;\"\u003eNo. This is a wet-joint style gasket. For 0M-and-up GM V6 and V8 small-block engines, it only applies when the engine has been fitted with the Dry Joint “Alternative” wet-joint replacement exhaust system.\u003c\/p\u003e\n \u003c\/div\u003e\n \u003c\/section\u003e\n\u003c\/div\u003e","brand":"Serdamarine","offers":[{"title":"Default Title","offer_id":45171576471603,"sku":"23GT296*2","price":11.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0699\/2930\/4115\/files\/marine-exhaust-part-3e4e1c75f5373431.png?v=1792750288"},{"product_id":"27-46820-exhaust-manifold-gasket-for-mercruiser-gm-big-block","title":"27-46820 Exhaust Manifold Gasket for MerCruiser GM Big Block","description":"\u003cdiv style=\"width:100%;max-width:960px;margin:0 auto;box-sizing:border-box;font-family:Arial,Helvetica,sans-serif;font-size:16px;line-height:1.75;color:#293a35;background:#ffffff;overflow-wrap:anywhere;\"\u003e\n \u003cdiv style=\"padding:28px 24px;margin:0 0 40px;border-top:5px solid #234d40;background:#f5f3ec;box-sizing:border-box;\"\u003e\n \u003cp style=\"margin:0 0 14px;color:#456052;font-size:12px;line-height:1.6;font-weight:700;letter-spacing:1.4px;text-transform:uppercase;\"\u003eSERDAMARINE \/ MARINE EXHAUST PARTS\u003c\/p\u003e\n \u003ch2 style=\"margin:0 0 18px;color:#203e32;font-family:Georgia,Times,serif;font-size:clamp(25px,4vw,34px);font-weight:400;line-height:1.25;\"\u003eExhaust Manifold Gasket — Adapter Plate to GM Manifold\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eThis aftermarket exhaust manifold gasket (OEM reference 27-46820) seals the exhaust manifold joint on specified MerCruiser, Volvo Penta, and OMC Cobra GM-based big-block V8 marine engines (7.4L \/ 454 CID, 8.1L \/ 496 CID, and 8.2L \/ 502 CID). It is also used at the adapter-plate-to-GM-exhaust-manifold interface in matching two-piece Ford 460-to-GM 454 manifold conversion assemblies.\u003c\/p\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eThis item is a single exhaust manifold gasket component, not a complete exhaust manifold assembly or a complete manifold gasket repair kit.\u003c\/p\u003e\n \u003c\/div\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003e27-46820 Exhaust Manifold Gasket for MerCruiser GM Big Block\u003c\/h2\u003e\n\u003cp style=\"margin:0 0 14px;\"\u003eAftermarket exhaust manifold gasket referenced to MerCruiser 27-46820 for the specified GM 7.4L, 8.1L and 8.2L big-block applications. Wet-joint and dry-joint conditions remain separated below.\u003c\/p\u003e\u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eEngine Applications\u003c\/h2\u003e\n\u003cul style=\"padding-left:20px;line-height:1.75;\"\u003e\n\u003cli\u003eMerCruiser MODEL 330–370, GM V8 Big Block, 454\/502 CID; Wet Joint; 1981 onward.\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM V8 7.4L \/ 454 CID, 8.1L \/ 496 CID and 8.2L \/ 502 CID applications; match the individual exhaust assembly.\u003c\/li\u003e\n\u003cli\u003eMerCruiser GM V8 Big Block, Dry Joint; match the specific manifold gasket interface. The 6-inch configuration designation is not a gasket measurement.\u003c\/li\u003e\n\u003cli\u003eChevrolet \/ Chevy 454 and 502 engine-base applications with the specified marine exhaust manifold.\u003c\/li\u003e\n\u003c\/ul\u003e\u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eReference Numbers\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eThe numbers below are provided as identification references across corresponding engine and aftermarket brands. They do not independently guarantee interchangeability across different manifold designs or indicate manufacturer identity; compare the complete part number (including any prefix, leading zero, and A1 suffix) along with the physical gasket shape.\u003c\/p\u003e\n \u003ctable style=\"width:100%;table-layout:fixed;border-collapse:collapse;text-align:left;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eMerCruiser Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e27-46820, 27-46820A1, 46820, 46820A1\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eVolvo Penta Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e3852472\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eOMC Cobra Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e0508878, 0778127, 0909613, 508878, 778127, 909613, 3852472\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eCrusader Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e96653\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eSierra Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e18-0418\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eGLM Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e33760, 37760\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eMallory Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e9-61400\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003c\/tbody\u003e\n \u003c\/table\u003e\n \u003cdiv style=\"margin:18px 0 0;padding:14px 16px;border-left:3px solid #8c622b;background:#faf5e9;color:#59421f;\"\u003e\n \u003cstrong\u003eReference Note:\u003c\/strong\u003e Do not select solely by GLM 37760; verify the exhaust manifold reference and gasket shape. Sierra 18-0418 is associated with use-with manifold references 18-1957-2, 18-1982, 18-1929, 18-1933, and 18-1898—those numbers identify exhaust manifolds, not engine models or replacement numbers for this gasket.\n \u003c\/div\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eSupplied Parts\u003c\/h2\u003e\n \u003cul style=\"margin:0;padding-left:22px;\"\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eExhaust manifold gasket\u003c\/li\u003e\n \u003c\/ul\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eService \u0026amp; Installation Notes\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eGeneral service guidance only. Use the service manual for your exact engine and exhaust configuration.\u003c\/p\u003e\n \u003col style=\"margin:0;padding-left:22px;list-style-type:decimal;\"\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eAllow the engine and exhaust system to cool completely, shut off the battery switch, and prevent accidental engine cranking before starting disassembly.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eSupport heavy exhaust manifold components during removal and installation to avoid damaging mounting studs, bolts, or mating surfaces.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eClean and inspect the mating faces on the exhaust manifold and cylinder head (or adapter plate). Remove old gasket material without gouging the sealing surfaces.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eCompare the new gasket directly against the removed gasket and the sealing interface to verify port alignment and bolt hole positions. On a matching two-piece Ford 460-to-GM 454 conversion arrangement, install this gasket specifically between the adapter plate and the GM exhaust manifold.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eTighten fasteners following the sequence and torque specifications in the engine manufacturer's service manual. After starting the engine, inspect the joint for exhaust leaks; shut down immediately and inspect if any abnormal leakage or temperature occurs.\u003c\/li\u003e\n \u003c\/ol\u003e\n \u003c\/section\u003e\n\n \u003cdiv style=\"margin:0 0 40px;padding:24px;border-top:1px solid #bdc9c0;border-bottom:1px solid #bdc9c0;background:#f5f3ec;box-sizing:border-box;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eThe Serdamarine Approach\u003c\/h2\u003e\n \u003cp style=\"margin:0;\"\u003eExhaust parts need a configuration match. Serdamarine focuses on marine exhaust manifolds and their related service parts. Application details, connection requirements and public reference numbers are presented together to support part selection.\u003c\/p\u003e\n \u003c\/div\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eQuestions Before Replacement\u003c\/h2\u003e\n \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eCan I order this gasket for any Ford 460 marine engine?\u003c\/h3\u003e\n \u003cp style=\"margin:0;\"\u003eNo. For Ford 460 applications, this gasket is only for the adapter-plate-to-GM-exhaust-manifold joint in a specific two-piece Ford 460-to-GM 454 manifold conversion assembly. It does not fit a standard Ford 460 cylinder-head-to-manifold joint.\u003c\/p\u003e\n \u003c\/div\u003e\n \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eIs this an exhaust elbow \/ riser gasket or a complete gasket kit?\u003c\/h3\u003e\n \u003cp style=\"margin:0;\"\u003eNeither. Exhaust manifold gaskets and exhaust elbow\/riser gaskets are separate parts serving different joints. This listing is for the individual exhaust manifold (or adapter-plate-to-GM-manifold) gasket, not a complete manifold gasket repair kit.\u003c\/p\u003e\n \u003c\/div\u003e\n \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eWhat are Sierra numbers 18-1957-2, 18-1982, 18-1929, 18-1933, and 18-1898?\u003c\/h3\u003e\n \u003cp style=\"margin:0;\"\u003eThose are Sierra exhaust manifold part numbers associated as \"use-with\" assemblies for Sierra gasket 18-0418. They identify the mating exhaust manifolds rather than engine model numbers or direct gasket replacement numbers.\u003c\/p\u003e\n \u003c\/div\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eRelated Service Parts\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eSierra reference 18-0418 lists the following associated exhaust manifold assemblies for use with this gasket style (manifolds are separate components and are not included with this gasket):\u003c\/p\u003e\n \u003cul style=\"margin:0;padding-left:22px;\"\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eSierra Exhaust Manifold References: 18-1957-2, 18-1982, 18-1929, 18-1933, 18-1898\u003c\/li\u003e\n \u003c\/ul\u003e\n \u003c\/section\u003e\n\u003c\/div\u003e","brand":"Serdamarine","offers":[{"title":"Default Title","offer_id":45172497252403,"sku":"24GK058","price":14.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0699\/2930\/4115\/files\/marine-exhaust-part-ac6ac11ab8c0ef7a.jpg?v=1792763653"},{"product_id":"27-863724-exhaust-elbow-riser-gasket-for-mercruiser-v6-v8-4-pack","title":"27-863724 Exhaust Elbow Riser Gasket for MerCruiser V6 V8 - 4 Pack","description":"\u003cdiv style=\"width:100%;max-width:960px;margin:0 auto;box-sizing:border-box;font-family:Arial,Helvetica,sans-serif;font-size:16px;line-height:1.75;color:#293a35;background:#ffffff;overflow-wrap:anywhere;\"\u003e\n \u003cdiv style=\"padding:28px 24px;margin:0 0 40px;border-top:5px solid #234d40;background:#f5f3ec;box-sizing:border-box;\"\u003e\n \u003cp style=\"margin:0 0 14px;color:#456052;font-size:12px;line-height:1.6;font-weight:700;letter-spacing:1.4px;text-transform:uppercase;\"\u003eSERDAMARINE \/ MARINE EXHAUST PARTS\u003c\/p\u003e\n \u003ch2 style=\"margin:0 0 18px;color:#203e32;font-family:Georgia,Times,serif;font-size:clamp(25px,4vw,34px);font-weight:400;line-height:1.25;\"\u003eExhaust Manifold Elbow Riser Gasket for MerCruiser Wet-Joint and Specified Dry-Joint Alternative Applications\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eThis aftermarket exhaust manifold-to-elbow\/riser joint gasket (referencing MerCruiser OEM 27-863724) seals the mounting interface between the exhaust manifold and riser elbow on specified MerCruiser V6 and V8 engines, including 350 MAG, 454 MAG, and 502 MAG models.\u003c\/p\u003e\n \u003cp style=\"margin:0;\"\u003eIt is configured for raw-water-cooled wet-joint systems across 1981 and up big-block and 1983 to 0M-serial small-block\/V6 applications, with a separately limited dry-joint alternative application for 0M and up GM V6 and small-block V8 engines.\u003c\/p\u003e\n \u003c\/div\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eConfiguration \u0026amp; Specifications\u003c\/h2\u003e\n \u003ctable style=\"width:100%;table-layout:fixed;border-collapse:collapse;text-align:left;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eJoint Location\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eExhaust manifold to elbow \/ riser joint\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eCooling Configuration\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eRaw water cooling\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eExhaust Joint Design\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eWet joint (with a separately limited dry-joint “alternative” application on 0M \u0026amp; up GM V6 \/ V8 S.B. engines)\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003c\/tbody\u003e\n \u003c\/table\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eEngine Applications\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eSelect this gasket by matching your engine model, full serial number, exhaust-joint design, and cooling configuration rather than relying on engine displacement alone. A restricted center-riser gasket should not be selected solely because its outline resembles an open or closed-cooling gasket.\u003c\/p\u003e\n \u003cul style=\"list-style:none;margin:0;padding:0;\"\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMerCruiser Model 175–205 (V6, GM 229 \/ 262 CID)\u003c\/strong\u003e — Years \/ Serial Range: 1983 – 0M SN#’s. Joint Configuration: Wet Joint. Cooling: Raw water cooling.\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n \u003c\/li\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMerCruiser Model 200–320 (V8 Small Block, GM 305 \/ 350 \/ 377 CID)\u003c\/strong\u003e — Years \/ Serial Range: 1983 – 0M SN#’s. Joint Configuration: Wet Joint. Cooling: Raw water cooling.\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n \u003c\/li\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMerCruiser Model 330–370 (V8 Big Block, GM 454 \/ 502 CID)\u003c\/strong\u003e — Years: 1981 \u0026amp; UP. Joint Configuration: Wet Joint. Cooling: Raw water cooling.\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n \u003c\/li\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMerCruiser GM V6 \/ V8 Small Block\u003c\/strong\u003e — Serial Range: 0M SN#’s \u0026amp; UP. Joint Configuration: Dry Joint “Alternative”.\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n \u003c\/li\u003e\n \u003cli style=\"margin:0;padding:17px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003cstrong\u003eMerCruiser Elbow-Joint Applications (350 MAG, 454 MAG, 502 MAG; 4.3L, 5.0L, 5.7L, 6.2L, 7.4L, 8.2L)\u003c\/strong\u003e — Applicable only when the engine serial number, wet-joint or specified dry-joint alternative design, and raw-water cooling configuration match the requirements listed above.\n \u003cspan style=\"display:block;margin:6px 0 0;color:#59421f;font-size:13px;font-weight:700;\"\u003eFits when specified\u003c\/span\u003e\n \u003c\/li\u003e\n \u003c\/ul\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eReference Numbers\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eThe numbers below are provided for part identification and cross-reference. They do not indicate original equipment manufacturer status or guarantee universal interchangeability across all MerCruiser V6 and V8 exhaust configurations.\u003c\/p\u003e\n \u003ctable style=\"width:100%;table-layout:fixed;border-collapse:collapse;text-align:left;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eMerCruiser Stern \/ Out Drive OEM References\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e41813, 27-41813, 27-860233, 27-863724, 27-863724Q, 863724B, 863724Q, 863724\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eOMC OEM Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e0508716\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eSierra Gasket Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e18-0897\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eGLM Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e30240\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eMallory Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e9-61413\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eRECMAR Gasket Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eREC27-863724Q\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eOther Cross-Reference Numbers\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eMC47-27-41813, 8503-GR\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eAssociated Exhaust Elbow \/ Assembly Reference Numbers (Not Gasket Numbers)\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eMC 20 99208; Sierra 18-1976-2, 18-1970-2; RECMAR MAR988, REC98504A3\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003c\/tbody\u003e\n \u003c\/table\u003e\n \u003cdiv style=\"margin:18px 0 0;padding:14px 16px;border-left:3px solid #8c622b;background:#faf5e9;color:#59421f;\"\u003e\n Note: Associated exhaust elbow and assembly numbers (such as Sierra 18-1976-2, 18-1970-2, RECMAR MAR988, REC98504A3, and MC 20 99208) identify related exhaust hardware that may use this gasket profile. This listing is for the gasket product only, not an exhaust manifold or elbow casting.\n \u003c\/div\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eSupplied Parts\u003c\/h2\u003e\n\u003cul style=\"padding-left:20px;line-height:1.75;\"\u003e\u003cli\u003e4 × Exhaust Manifold Elbow Riser Gasket — identical gaskets with the same OEM reference: 27-863724Q.\u003c\/li\u003e\u003c\/ul\u003e\u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eService \u0026amp; Installation Notes\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eGeneral service guidance only. Use the service manual for your exact engine and exhaust configuration.\u003c\/p\u003e\n \u003col style=\"margin:0;padding-left:22px;list-style-type:decimal;\"\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eEnsure the engine is shut off, completely cool, and secured against accidental starting before servicing the exhaust system.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eDrain the exhaust manifold and riser water passages in accordance with your engine service manual before loosening the elbow hardware.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eSupport the weight of the exhaust elbow or riser during removal and installation, and clean both mating surfaces thoroughly without gouging the sealing flanges.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eVerify that the gasket water passages and orientation match the manifold-to-elbow joint design and cooling flow path specified for your engine serial number.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eTighten fasteners to the sequence and torque values specified in the factory service manual. After reassembly, run the engine with proper cooling water supply and inspect the joint for water or exhaust leaks; stop the engine immediately if any abnormal leakage or temperature rise occurs.\u003c\/li\u003e\n \u003c\/ol\u003e\n \u003c\/section\u003e\n\n \u003cdiv style=\"margin:0 0 40px;padding:24px;border-top:1px solid #bdc9c0;border-bottom:1px solid #bdc9c0;background:#f5f3ec;box-sizing:border-box;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eThe Serdamarine Approach\u003c\/h2\u003e\n \u003cp style=\"margin:0;\"\u003eExhaust parts need a configuration match. Serdamarine focuses on marine exhaust manifolds and their related service parts. Application details, connection requirements and public reference numbers are presented together to support part selection.\u003c\/p\u003e\n \u003c\/div\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eQuestions Before Replacement\u003c\/h2\u003e\n \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eDoes this gasket fit all MerCruiser 4.3L, 5.0L, 5.7L, 6.2L, 7.4L, and 8.2L engines?\u003c\/h3\u003e\n \u003cp style=\"margin:0;\"\u003eNo. Engine displacement or model designation (such as 350 MAG, 454 MAG, or 502 MAG) alone does not determine gasket fitment. This gasket applies to raw-water-cooled wet-joint systems on V6 (229\/262 CID) and small-block V8 (305\/350\/377 CID) engines from 1983 through 0M serial numbers, big-block V8 (454\/502 CID) wet-joint systems from 1981 and up, and the specified dry-joint alternative application on 0M and up GM V6 and small-block V8 engines.\u003c\/p\u003e\n \u003c\/div\u003e\n \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eCan this gasket be used interchangeably with open or closed-cooling riser gaskets of a similar shape?\u003c\/h3\u003e\n \u003cp style=\"margin:0;\"\u003eNo. A restricted center-riser gasket or raw-water gasket should not be substituted solely because its outer footprint resembles an open full-flow or closed-cooling block-off gasket. Always match the cooling configuration and joint type to your engine's exact serial number and exhaust system design.\u003c\/p\u003e\n \u003c\/div\u003e\n \u003c\/section\u003e\n\u003c\/div\u003e","brand":"Serdamarine","offers":[{"title":"Default Title","offer_id":45172501053491,"sku":"23GT303*4","price":16.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0699\/2930\/4115\/files\/marine-exhaust-part-2291d58177cd42db.png?v=1792763708"},{"product_id":"16951q1-brass-cooling-drain-plug-for-mercruiser-1-4-npt","title":"16951Q1 Brass Cooling Drain Plug for MerCruiser 1\/4 NPT","description":"\u003cdiv style=\"width:100%;max-width:960px;margin:0 auto;box-sizing:border-box;font-family:Arial,Helvetica,sans-serif;font-size:16px;line-height:1.75;color:#293a35;background:#ffffff;overflow-wrap:anywhere;\"\u003e\n \u003csection style=\"padding:28px 24px;margin:0 0 40px;border-top:5px solid #234d40;background:#f5f3ec;box-sizing:border-box;\"\u003e\n \u003cp style=\"margin:0 0 14px;color:#456052;font-size:12px;line-height:1.6;font-weight:700;letter-spacing:1.4px;text-transform:uppercase;\"\u003eSERDAMARINE \/ MARINE EXHAUST PARTS\u003c\/p\u003e\n \u003ch2 style=\"margin:0 0 18px;color:#203e32;font-family:Georgia,Times,serif;font-size:clamp(25px,4vw,34px);font-weight:400;line-height:1.25;\"\u003e16951Q1 Brass Cooling Drain Plug for MerCruiser 1\/4 NPT\u003c\/h2\u003e\n\u003cp style=\"margin:0 0 14px;\"\u003eAftermarket brass cooling-system drain plug referenced to Mercury 16951Q1 for compatible GM-based MerCruiser engine-block and manifold ports. It uses a 1\/4-inch NPT thread; compare the original reference and port specification.\u003c\/p\u003e\u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eConfiguration \u0026amp; Specifications\u003c\/h2\u003e\n \u003ctable style=\"width:100%;table-layout:fixed;border-collapse:collapse;text-align:left;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eComponent Function\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eCooling-system drain plug \/ bleed screw\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eThread Specification\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e1\/4\" NPT\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eMaterial\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eBrass\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eInstallation Location\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eCompatible GM cylinder block or exhaust manifold cooling-system drain and bleed ports\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003c\/tbody\u003e\n \u003c\/table\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eEngine Applications\u003c\/h2\u003e\n\u003cul style=\"padding-left:20px;line-height:1.75;\"\u003e\u003cli\u003eMerCruiser GM-based sterndrive or inboard engine block \/ manifold cooling-system drain or bleed port; 1\/4-inch NPT, brass.\u003c\/li\u003e\u003c\/ul\u003e\u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eReference Numbers\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eThe numbers below are provided for part identification and cross-reference only; they do not establish manufacturer identity or guarantee interchangeability without matching port thread and location.\u003c\/p\u003e\n \u003ctable style=\"width:100%;table-layout:fixed;border-collapse:collapse;text-align:left;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eMercury \/ Mariner OEM References\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e16951A1, 16951T1, 16951Q1, 22-16951Q1, 22-16951A1, 22-16951T1, 22-64426, 22-87238\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eOMC OEM Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e379957\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eVolvo Penta OEM Reference\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003e82745\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eAftermarket References\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eSierra 18-4218; GLM 13993; RECMAR REC82745\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003ctr\u003e\n \u003cth scope=\"row\" style=\"width:36%;padding:13px 10px 13px 0;border-bottom:1px solid #e0e5df;vertical-align:top;text-align:left;font-size:14px;font-weight:700;color:#456052;\"\u003eAlternate Packaging References\u003c\/th\u003e\n \u003ctd style=\"padding:13px 0 13px 10px;border-bottom:1px solid #e0e5df;vertical-align:top;\"\u003eSierra 18-4218D (display-packaged version of 18-4218); Sierra 18-3223-9 (separate bulk-pack reference). These packaging identifiers are for cross-reference only and do not define the packaging of this listing.\u003c\/td\u003e\n \u003c\/tr\u003e\n \u003c\/tbody\u003e\n \u003c\/table\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eSupplied Parts\u003c\/h2\u003e\n \u003cul style=\"margin:0;padding-left:22px;\"\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eBrass cooling-system drain plug \/ bleed screw (1\/4\" NPT)\u003c\/li\u003e\n \u003c\/ul\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eService \u0026amp; Installation Notes\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eGeneral service guidance only. Use the service manual for your exact engine and exhaust configuration.\u003c\/p\u003e\n \u003col style=\"margin:0;padding-left:22px;list-style-type:decimal;\"\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eShut down the engine, prevent accidental starting, and allow the engine block, manifold, and cooling water to cool completely before removing any drain plug.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eRemove the existing fitting and inspect the cylinder-block or manifold port threads for corrosion, rust scale, or debris that could block cooling-system drainage or damage the brass threads.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eCompare the removed plug with the replacement to verify the 1\/4\" NPT thread specification before threading it into the port by hand to avoid cross-threading.\u003c\/li\u003e\n \u003cli style=\"margin:0 0 12px;\"\u003eTighten according to the engine manufacturer's service manual procedures and inspect the port for cooling-water leaks during initial operation; shut down and inspect if any leakage occurs.\u003c\/li\u003e\n \u003c\/ol\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;padding:24px;border-top:1px solid #bdc9c0;border-bottom:1px solid #bdc9c0;background:#f5f3ec;box-sizing:border-box;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eThe Serdamarine Approach\u003c\/h2\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eExhaust parts need a configuration match. Serdamarine focuses on marine exhaust manifolds and their related service parts. Application details, connection requirements and public reference numbers are presented together to support part selection.\u003c\/p\u003e\n \u003c\/section\u003e\n\n \u003csection style=\"margin:0 0 40px;\"\u003e\n \u003ch2 style=\"margin:0 0 18px;padding:0 0 10px;border-bottom:1px solid #bdc9c0;color:#234d40;font-family:Georgia,Times,serif;font-size:25px;font-weight:400;line-height:1.35;\"\u003eQuestions Before Replacement\u003c\/h2\u003e\n \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eCan this plug be used for a 1\/8\" NPT or metric 10 × 1 drain port?\u003c\/h3\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eNo. This fitting is machined specifically for a 1\/4\" NPT pipe thread port on compatible GM engine blocks and manifolds. It is not interchangeable with 1\/8\" NPT or 10 × 1 threaded drain fittings.\u003c\/p\u003e\n \u003c\/div\u003e\n \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eDoes this fit lower-unit gearcase drain holes or water-flush ports?\u003c\/h3\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eNo. Although cataloged alongside general drain hardware, this brass plug is intended only for engine-block and exhaust-manifold cooling-system bleed or drain ports using a 1\/4\" NPT thread, not lower-unit gear-oil drains or flush connectors.\u003c\/p\u003e\n \u003c\/div\u003e\n \u003cdiv style=\"margin:0;padding:18px 0;border-bottom:1px solid #dce3dc;\"\u003e\n \u003ch3 style=\"margin:0 0 10px;color:#234d40;font-size:17px;line-height:1.5;font-weight:700;\"\u003eWhat do the Sierra 18-4218D and 18-3223-9 references indicate?\u003c\/h3\u003e\n \u003cp style=\"margin:0 0 14px;\"\u003eSierra 18-4218D is a display-packaged version of 18-4218, and Sierra 18-3223-9 is a bulk-pack reference for the same 1\/4\" NPT brass drain plug design. They are listed for part cross-reference only and do not represent a bulk package or complete valve kit for this product.\u003c\/p\u003e\n \u003c\/div\u003e\n \u003c\/section\u003e\n\u003c\/div\u003e","brand":"Serdamarine","offers":[{"title":"Default Title","offer_id":45172507836467,"sku":"25PK052","price":16.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0699\/2930\/4115\/files\/marine-exhaust-part-3521e5972eff7a1a.jpg?v=1792763877"}],"url":"https:\/\/serdamarine.com\/collections\/mercruiser-7-4l-454-mag-v-8-sterndrive-0b721206-thru-0d805068.oembed","provider":"我的商店","version":"1.0","type":"link"}