27-864549A02 Dry-Joint Riser Block-Off Gasket Set for MerCruiser

SERDAMARINE / MARINE EXHAUST PARTS

Dry-Joint Exhaust Elbow/Riser Block-Off Gasket Set — 2 Pieces

This two-piece set of aftermarket dry-joint exhaust elbow/riser block-off gaskets corresponds to MerCruiser reference 27-864549A02 for compatible closed-cooling applications on GM V6 and small-block V8 (4.3L, 5.0L, 5.7L, and 6.2L) engines. It is the block-off (closed) flow version used at dry-joint closed manifold and riser connections—including 2002–2004 7° and 2005–2010 14° dry-joint configurations—rather than the restrictor or full-flow (open) gasket versions.

Configuration & Specifications

Engine Applications

Engine displacement alone is not enough to choose the correct dry-joint gasket; verify your installed exhaust joint, closed-cooling layout, and block-off flow requirement against the applications below.

• MerCruiser GM V6 & V8 Small Block (2002–2004) — Dry Joint 7° configuration; Block Off (Closed Cooling) exhaust elbow/riser connection. Fits when specified
• MerCruiser GM V6 & V8 Small Block (2005–2010) — Dry Joint 14° configuration; Block Off (Closed Cooling) exhaust elbow/riser connection. Fits when specified
• MerCruiser V6 & V8 Small Block (2002 onward) — Dry Joint configuration with Block Off (Closed Cooling). Fits when specified
• MerCruiser 4.3L, 5.0L, 5.7L & 6.2L — Engines utilizing the Dry Joint closed manifold and riser configuration with Block Off (Closed Cooling). Fits when specified

Not Suitable For

• Restrictor or Full-Flow (Open) Dry-Joint Applications — This is the block-off/closed gasket version and cannot be used where a restrictor or full-flow/open gasket is required. Not suitable

Additional model-specific applications

• MerCruiser GM V8 S.B., 2002–2004, Dry Joint 7°, Closed Cooling, Block Off.
• MerCruiser GM V8 S.B., 2005–2010, Dry Joint 14°, Closed Cooling, Block Off.
• MerCruiser 4.3L application, Dry Joint Closed Manifold and Riser, Closed Cooling, Block Off.
• MerCruiser 5.0L application, Dry Joint Closed Manifold and Riser, Closed Cooling, Block Off.
• MerCruiser 5.7L application, Dry Joint Closed Manifold and Riser, Closed Cooling, Block Off.
• MerCruiser 6.2L application, Dry Joint Closed Manifold and Riser, Closed Cooling, Block Off.

Reference Numbers

These part numbers are provided for identification and cross-reference purposes only; they do not alone guarantee interchangeability across different flow configurations or indicate manufacturer identity.

Supplied Parts

• 2 × Dry-joint exhaust elbow/riser block-off gaskets

Service & Installation Notes

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

1. Shut down the engine, allow all exhaust and cooling components to cool completely, and disconnect the battery to prevent accidental starting before disassembly.
2. Support the exhaust elbow/riser securely during removal, and clean both the dry-joint manifold and elbow mating surfaces thoroughly while protecting the machined sealing faces from gouges or scratches.
3. Compare the new block-off gaskets directly against the removed gaskets and the manifold/riser cooling passages to verify that the closed/block-off configuration matches the engine's closed-cooling layout.
4. Install the gaskets and tighten the elbow/riser fasteners following the sequence and specifications in your engine service manual. After reassembly, inspect the joint during initial operation and shut down immediately if any exhaust or coolant leakage 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