Cometic AMC 390/401 Gen-3 V8 .045in MLS Cyl Head Gasket-4.380in Bore-With Indy Heads-18 Bolt Head

Starting with a compressed operating thickness of 0.036 inches, this Cometic Multi-Layer Steel (MLS) head gasket is built for serious performance. It’s specifically designed for AMC 390/401 Gen-3 V8 engines with a 4.380-inch bore, particularly when using Indy Heads and an 18-bolt configuration. This gasket is a solid choice for rebuilding or upgrading engines that push beyond stock power levels.

The construction uses multiple layers of stainless steel, which gives it strength and the ability to rebound, helping it resist corrosion. The outer layers are embossed and coated on both sides with Viton, a heat-resistant rubber material rated up to 482°F (250°C). This coating handles tough sealing environments and varying surface finishes, making it suitable for both aluminum-to-aluminum and aluminum-to-cast iron block setups. The center layer is stainless steel and can be varied in thickness to meet specific engine build requirements, like the 0.045-inch thickness of this particular gasket.

This gasket is designed to provide maximum sealing performance for high-output engines and doesn't require additional sealants. It fits a range of vehicles, including models like the American Motors Javelin, Jeep Cherokee, and Jeep Wagoneer from the 1970s.