Cometic GM Gen II / Mark IV Big Block (396 / 402 / 427) 4.630in Bore .070in MLS-5 Head Gasket

This Cometic Multi-Layer Steel (MLS) head gasket is built with a compressed operating thickness of 0.070 inches and a 4.630-inch bore, specifically designed for GM Gen II and Mark IV Big Block engines like the 396, 402, and 427. The multi-layer stainless steel construction offers increased strength and resilience, making it a solid choice for high-output applications where reliable sealing is critical.

The outer layers of this gasket are coated with Viton, a heat-resistant rubber material capable of withstanding temperatures up to 482 degrees Fahrenheit. This coating ensures a strong seal even under demanding conditions and across different material combinations, such as aluminum heads to cast iron blocks. Because it's a multi-layer steel design, it doesn't require any additional sealants, simplifying the installation process. The center shim layer is stainless steel and can be varied to meet different thickness needs, allowing for precise engine building.

This gasket fits a wide range of Chevrolet vehicles from the mid-60s through the late 70s, including popular models like the Impala, Chevelle, and C10 Pickup. It's a well-built component designed to handle the stresses of a big block engine.