Cometic C5639-030 GM/Mercury Marine Gen-IV Big Block MLS Cylinder Head Gasket - V8

The Cometic C5639-030 is a precision-engineered Multi-Layer Steel (MLS) cylinder head gasket designed specifically for GM and Mercury Marine Gen-IV Big Block V8 engines with a 1050 cubic inch displacement. This high-performance gasket features a .030" (0.76mm) compressed thickness and accommodates a 4.530" bore diameter, making it ideal for high-compression marine and performance applications.

Key Features:

• Multi-Layer Steel (MLS) construction provides superior sealing and durability under extreme pressures and temperatures
• 0.030" compressed thickness for precise compression ratio tuning
• 4.530" bore diameter specifically sized for Gen-IV big block applications
• Includes two slotted lifter valley bolt holes for proper engine assembly
• Compatible with GM and Mercury Marine 1050 Gen-IV Big Block V8 engines
• Engineered to handle the demanding conditions of marine and high-performance environments

Cometic's MLS gaskets utilize multiple layers of stainless steel with advanced coating technology to create a reliable seal that can withstand extreme cylinder pressures, temperature cycling, and engine movement. The slotted lifter valley bolt design ensures proper clamping force distribution across the sealing surface. This gasket is an essential component for engine rebuilds, performance upgrades, or marine engine maintenance where reliability and precision are critical.