27-863724Q Restrictor Exhaust Elbow Riser Gasket for MerCruiser V6 V8

SERDAMARINE / MARINE EXHAUST PARTS

Exhaust Manifold Elbow Riser Gasket for MerCruiser Raw-Water-Cooled Restrictor Joints

This individual exhaust manifold-to-elbow/riser gasket (referenced to MerCruiser 27-863724Q and restrictor references such as 27-860233 and Sierra 18-0897) is for raw-water-cooled manifold joints on specified MerCruiser GM V6, small-block V8, and big-block V8 stern drive applications. It fits listed wet-joint systems within the specified year and 0M serial-number boundaries, as well as the raw-water gasket position in compatible GM V6/V8 small-block Dry Joint “Alternative” systems (0M serial numbers and up), and is not a complete manifold gasket kit or a universal original dry-joint gasket.

Configuration & Specifications

Engine Applications

This gasket services specified MerCruiser Stern Drive raw-water-cooled exhaust joints across the GM V6, small-block V8, and big-block V8 families listed below. Verify whether your manifold-to-elbow joint requires a restricted (restrictor), open, or closed-cooling gasket and match your engine model, displacement, joint design, and serial-number generation before ordering.

• MerCruiser Stern Drive MODEL 175-205 — V6, GM 229/262 CID — Years / Serial Numbers: 1983 - 0M SN#’s. Exhaust Configuration: Wet Joint, raw water cooling, restricted elbow/riser gasket position. Fits when specified
• MerCruiser Stern Drive MODEL 200-320 — V8 S.B. (Small Block), GM 305/350/377 CID — Years / Serial Numbers: 1983 - 0M SN#’s. Exhaust Configuration: Wet Joint, raw water cooling, restricted elbow/riser gasket position. Fits when specified
• MerCruiser Stern Drive MODEL 330-370 — V8 B.B. (Big Block), GM 454/502 CID — Years: 1981 & UP. Exhaust Configuration: Wet Joint, raw water cooling, restricted elbow/riser gasket position. Fits when specified
• MerCruiser Stern Drive GM V6 / V8 S.B. (Small Block) Dry Joint “Alternative” — Serial Numbers: 0M SN#’s & UP. Exhaust Configuration: Raw-water gasket position in a compatible Dry Joint “Alternative” exhaust system (do not treat as a universal original dry-joint gasket). Fits when specified
• MerCruiser Stern Drive 350 MAG, 454 MAG, 502 MAG & 4.3L, 5.0L, 5.7L, 6.2L, 7.4L, 8.2L — Applicable only when equipped with the matching raw-water-cooled Wet Joint or GM V6/V8 S.B. Dry Joint “Alternative” exhaust system and within the corresponding engine family, year, and serial-number limits listed above. Fits when specified

Reference Numbers

These numbers are provided as identification references for part lookup and do not by themselves guarantee universal interchangeability or indicate the manufacturer of this aftermarket part.

Supplied Parts

This part is sold individually as a gasket and is not a complete exhaust manifold gasket repair kit.

• Exhaust Manifold Elbow Riser Gasket

Service & Installation Notes

General service guidance only. Use the service manual for your exact engine and exhaust configuration.

1. Shut off the engine, disconnect the battery to prevent accidental starting, and allow the exhaust system to cool completely before disassembly.
2. Support the exhaust elbow/riser securely when removing fasteners, and clean both the manifold and elbow mating surfaces thoroughly without gouging or warping the sealing planes.
3. Compare the water-passage slots of the replacement restrictor gasket against your exhaust system diagram to confirm the required flow configuration and orientation; do not substitute an open (full-flow) or closed-cooling (block-off) gasket where a restrictor gasket is specified.
4. After reassembly to the engine manufacturer's specifications, supply cooling water before starting the engine and inspect the manifold-to-elbow joint for water or exhaust leaks; shut down immediately and inspect if any leakage or abnormal temperature occurs.

The Serdamarine Approach

Exhaust 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.

Questions Before Replacement