Edelbrock Performer Dual-Plane 4V Aluminum Intake Manifold. Designed for Street use on all 66 & Newer 273/318LA/340/360 Small Block Engines. Operates from Idle to 5500 RPM. This is a Street legal Manifold for 66-72 & 73 Non-California Vehicles without EGR. Recommended Carburetor size is 600-650 CFM. Port exit Dimensions are: .97″ x 1.95″. NOT for use on Marine Engines used in Salt Water. Will NOT fit the Earlier 64-65 273 Engines, 318 Poly(A-Engines), or 1992 and later Magnum engines. Made in the USA.