Cometic C5638-045 GM/Mercury Marine Gen-IV Big Block MLS Cylinder Head Gasket - V8

The Cometic C5638-045 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 delivers exceptional sealing reliability for demanding marine and automotive applications.

Key Specifications:

• Bore Size: 4.500 inches
• Gasket Thickness: .045 inches (1.14mm)
• Construction: Multi-Layer Steel (MLS) design
• Compatibility: GM/Mercury Marine Gen-IV Big Block V8 engines
• Includes: Two slotted lifter valley bolts

Multi-Layer Steel Technology: Cometic's MLS gaskets feature multiple layers of stainless steel with advanced coating technology that provides superior thermal resistance and combustion sealing. The embossed layers create micro-sealing pressure points that conform to surface irregularities, ensuring optimal sealing even under extreme cylinder pressures and temperature cycling.

Performance Benefits: This gasket is ideal for both stock and modified engines, offering exceptional durability in high-performance marine environments where reliability is critical. The MLS construction accommodates engine movement and thermal expansion while maintaining consistent clamping pressure across the entire sealing surface.

The included slotted lifter valley bolts provide proper fastening for the lifter valley area, ensuring complete sealing of the engine's internal oil passages. This gasket is a direct-fit solution for Gen-IV big block rebuilds and performance upgrades.