Edelbrock Part PN 7521-CP RPM Air-Gap intake manifold is designed for the Small-Block Ford 289-302 CID V8 including 331-347 stroker applications. The RPM Air-Gap incorporates the same race-winning technology that's been used on our Victor Series competition intakes and is the perfect manifold for hot rodders, street custom enthusiasts, bracket racers or any builder looking for optimum performance in the 1,500-6,500 RPM range with a serious look of horsepower under the hood. The Air-Gap design features an open air space under the plenum that separates the runners from the hot engine resulting in a cooler, denser charge for more power. The 7521 RPM Air-Gap features larger runners (7% at the plenum entries) than the standard 7121 Performer RPM design that is beneficial to larger CID stroker engines. The PN 7521-CP version comes with a brilliant Chrome plasma finish that is durable and easy to maintain. The 7521-CP includes nitrous bosses but no provision for exhaust heated chokes and no exhaust crossover. Edelbrock carbs will work with Ford automatic overdrive trans (AOD) when used with Lokar bracket SRK-4000. For more info go to www.lokar.com.