These 360 degree Speedmaster single plane manifolds make their power in the 1,500 to 6,800 rpm range, which makes them the ultimate manifolds for high-performance street, drag, marine, and Oval Track engines. The carburetor mounting pad is designed to accept all current aftermarket performance carburetors, and includes an open-style plenum for increased flow. Best suited to engines equipped with aggressive camshafts, headers, and high-output ignitions, these intakes are sure to put a smile on your face.