Cometic Chevrolet Mark-IV/GM Gen-V/VI Big Block V8 .040in MLS Cylinder 4.630in Bore

This Cometic Multi-Layer Steel (MLS) head gasket is built with multiple embossed layers of stainless steel, featuring an outer coating of Viton rubber. The compressed operating thickness is .040 inches, and it's designed for a 4.630 inch bore, making it suitable for aftermarket heads where customization of water ports might be needed. These gaskets are a solid choice for high-output Chevrolet Mark-IV, GM Gen-V/VI Big Block V8 engines, offering maximum sealing performance without requiring additional sealants.

The multi-layer stainless steel construction provides increased strength and the ability to rebound, which helps resist corrosion. The Viton coating on the outer layers is a heat-resistant elastomer capable of handling harsh sealing environments and various load conditions, up to 482 degrees Fahrenheit. The center shim layer is uncoated stainless steel, allowing for thickness adjustments to meet specific requirements. This design is effective for sealing between aluminum heads and aluminum blocks, as well as aluminum heads and cast iron blocks, handling the shearing forces that can occur between dissimilar materials.

This gasket fits a wide range of vehicles, including popular models like the 1965-1975 Chevrolet Impala, 1968-1974 Chevrolet C10 Pickup, and 1967-1972 Chevrolet Camaro. It's designed to meet the demands of performance applications where reliable sealing is critical.