Mr. Gaskets ultra-seal head gasket is a 5 layer composite construction including a graphite/perforated steel outer layers. The graphite core provides excellent thermo-conductivity, transfers heat away from hot spots in head to coolant passages, preventing gasket burn-out. The ultra-seal head gasket provides excellent stability, compressibility and high temperature endurance. Coated with high temperature silicone to ensure seal of engine fluids. Will not brinell (indent) aluminum cylinder heads. For high performance street, drag race and oval track applications. Used for Small Block Chevrolet 350; 1992-97.