Cometic Chevrolet 348/409 W-Series Big Block V8 .045in MLS Cylinder Head Gasket - 4.200in Bore

When you're rebuilding the top end of your Chevrolet 348 or 409 W-Series Big Block V8, a reliable head gasket is crucial. This Cometic Multi-Layer Steel (MLS) gasket is built to handle the demands of these powerful engines, offering a 4.200-inch bore and a compressed thickness of 0.036 inches, with an uncompressed thickness of 0.045 inches. It's designed to provide maximum sealing performance without needing additional sealants, making installation more straightforward.

Cometic constructs these MLS gaskets from multiple layers of stainless steel, which gives them increased strength and the ability to rebound, helping to resist corrosion. The outer layers are embossed and coated on both sides with Viton, a heat-resistant rubber material that can handle tough sealing environments and various surface finishes. This construction is suitable for mating aluminum heads to either aluminum or cast iron blocks, as it can manage the shearing forces that can occur between different metals. The center layer is stainless steel, allowing for adjustments in thickness to meet specific engine requirements.

This gasket is a solid option for many classic Chevrolet models from the late 1950s and early 1960s, including Impalas, Bel Airs, and C/K series trucks. Ensure you check the fitment data to confirm it's the right gasket for your specific vehicle.