Cometic GM LS1 SB 4.000 inch Bore .040 inch MLS Head Gasket

This is a Cometic Multi-Layer Steel (MLS) head gasket designed for GM LS Gen-3 and Gen-4 small block V8 engines. It features a 4.000 inch bore and a compressed thickness of 0.040 inches. MLS gaskets are built with multiple layers of stainless steel, giving them increased strength and the ability to rebound and resist corrosion. They are ideal for sealing between aluminum heads and either aluminum or cast iron blocks, handling the shearing forces that can occur between these materials. The outer layers are coated with Viton, a heat-resistant rubber material that can handle demanding sealing environments and various surface finishes, meaning you don't need additional sealants.

The multi-layer design provides maximum sealing performance, which is important for high-output engines. The center layer is uncoated stainless steel and can be varied to achieve different thickness requirements, like this 0.040 inch version. This gasket fits a wide range of GM vehicles, including models like the Chevrolet Corvette, Cadillac CTS, and Chevrolet Silverado 1500.