Edelbrock part #7531 RPM Air-Gap AMC intake manifold is designed for 1970-91 304-401 c.i.d. V8 applications. The RPM Air-Gap intake manifold incorporate the same race-winning technology as our Victor Series competition intakes. The air-gap design features an open air space that separates the runners from the hot engine oil for a cooler, denser charge and more power. Includes standard oil fill and PCV provisions as well as early air conditioning support bracket accessory bosses. For square-bore carbs. No provision for exhaust-heated chokes. No exhaust crossover.