This rocker cover gasket seals the joint between the valve cover and the cylinder head on the host engine. It prevents oil leakage and maintains crankcase pressure within the specified range. A degraded gasket allows oil to weep onto the exterior of the engine, which can lead to a low oil level and contamination of the alternator or exhaust manifold. The gasket is manufactured by Glaser to match the original sealing profile, ensuring it compresses evenly against the cover flange without requiring additional sealant. On reinstallation, clean both mating surfaces and tighten the cover bolts in the sequence and to the torque value specified for the engine.