Designed for street 396-502 c.i.d. Chevy V8s with large oval-port cylinder heads (1975 and earlier), the new RPM Air-Gap incorporates the same race-winning technology that's been used on our Victor Series competition intakes for years.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. 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. No provision for exhaust heated chokes and no exhaust crossover. Will not fit under stock hood of Corvette, 1965-67 Chevelle or 1967-81 Camaro. Unlike traditional chromed or polished aluminum finishes, PermaStar won't oxidize, fade or turn blue and cleans easily.