Cometic C5639-080 GM/Mercury Marine Gen-IV Big Block MLS Cylinder Head Gasket - V8

The Cometic C5639-080 is a high-performance Multi-Layer Steel (MLS) cylinder head gasket engineered specifically for GM and Mercury Marine 1050 Gen-IV Big Block V8 engines. This precision-manufactured gasket features a .080" (2.0mm) compressed thickness and is designed to accommodate a 4.530" cylinder bore diameter.

Key Features:

• Multi-Layer Steel (MLS) construction for superior sealing and durability under high compression and temperature conditions
• 0.080" compressed gasket thickness provides optimal sealing with performance cylinder heads
• 4.530" bore diameter designed for big block applications
• Includes provisions for 2 slotted lifter valley bolts for proper engine assembly
• Marine-grade construction suitable for both automotive and marine applications
• Precision-cut design ensures consistent compression and eliminates leak paths

Cometic MLS head gaskets feature multiple layers of stainless steel with elastomeric coatings that provide exceptional micro-sealing at the head-to-block surface. The embossed layers create a superior seal around combustion chambers, coolant passages, and oil return holes, making this gasket ideal for high-performance street engines, race applications, and marine performance builds.