Edelbrock part #7501 RPM Air-Gap #7501 intake manifold is designed for 1955-86 262-400 c.i.d. Chevrolet V8 applications. The award-winning RPM Air-Gap intake manifold incorporates the same race-winning technology that’s used on our Victor Series competition intakes. The air-gap design features an open-air space that separates the runners from the hot engine oil resulting in a cooler, denser charge for more power.