The Edelbrock RPM Air-Gap 2-O #75613 intake manifold is designed for street 396-502 c.i.d. Chevy V8's with large oval-port cylinder heads (1975 and earlier) or Edelbrock Performer/Performer RPM heads. The RPM Air-Gap incorporates the same race-winning technology that’s been used on our Victor Series competition intakes for decades. 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. The RPM Air-Gap 2-O #75613 intake manifold is a dual-plane, high-rise design with a 180-degree firing order to produce incredible top-end horsepower while retaining good throttle response. The larger plenum and runners match the free-flowing exhaust, high-lift cams and other modifications of a high output engine. This manifold is intended for high-performance street or competition engines that run up to 6500 rpm. Includes rear water outlets, two distributor clamp locations and nitrous bosses. Accepts all late model alternator and A/C brackets for the street. For square bore carburetors only. Will not fit under stock hood of Corvette, 1964-67 Chevelle or 1967-81 Camaro. No provision for exhaust heated chokes and no exhaust crossover.