The Edelbrock Performer Air-Gap #2604 intake manifold is designed for 1987-95 cast iron heads with canted center bolt holes small-block Chevys, the Performer Air-Gap features the air-gap design for the ultimate street performance in the idle to 5500 rpm range. This design features an open air space that separates the runners from the hot engine oil resulting in a cooler, denser charge for more power. High-velocity runners deliver excellent throttle response throughout the power band. The great looks of the Performer Air-Gap along with the solid idle to 5500 rpm performance makes this an ideal choice for street rods and street machines. Fits spread-bore or square-bore carburetors. Will not fit under stock Corvette hood.