Keith Dorton Series Intake Chevy Small Block V8 Keith Dorton Series Intake Manifold 1957-1986 262ci-400ci, 1987-later with Aluminum Heads HolleyThis is a great manifold designed for competition engines built for circle track and drag racing using 23o standard port heads. Ideal for classes that require cast iron heads that require an unported intake manifold. Features and Benefits: Isolated Water cross over Square Bore Carburetor Mounting Flange Power band: 4500 8500 RPM Single Plane with Isolated Plenum Port Size: 2. 00 inch height 1. 20 inch width Height: Front 6. 13 inch, Rear 6. 13 inch