Ultra-Seal Intake Manifold Gaskets .120 Inch Thickness Fits 1965-1990 Chevrolet 396-454 Big Block with Rectangle Raised Port Heads. No upper bolt holes. 1.85 x 2.55 Inch Mr GasketUltra Seal intake manifold Gaskets are manufactured from cellulose nitrile composition Gasket material. Provides excellent sealing and durability. Incorporates Silicone beading around each intake and water outlet port to provide additional sealing strength on both sides of each Gasket. No Gasket sealer required. For OE replacement, high performance street, drag race and oval track use. Includes manifold end seals and distributor Gasket. Manufactured