Edelbrock 7581-BP RPM Air-Gap Intake Manifold for Small Block Ford 351WThe Edelbrock RPM Air Gap 351W #7581 BP intake manifold is designed for street and high performance 351 427 c. i. d. 351W Ford V8's, the RPM Air Gap incorporates the same race winning design 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. Larger cross sectional area and a taller