The Air-Gap design leaves an open space between the runners and the lifter valley, so hot oil is not in direct contact with the incoming charge. Cooler air is denser air, which is where the power comes from. The tradeoff is that the runners sit higher and the manifold does not warm the intake charge in cold weather, so it suits a performance build over a daily driver in a cold climate.

Edelbrock 7516-CP RPM Air-Gap Manifold Specifications:

• Dual plane Air-Gap design, cast aluminum, chrome plasma finish.
• For small-block Chevrolet Vortec cylinder heads.
• 1,500 to 6,500 rpm operating range, square bore 4150 flange.
• Heights: 4.2 in. front, 4.72 in. center.
• Non-EGR. Gaskets are not included. Check hood clearance, as Air-Gap manifolds are taller.