This high performance aluminum manifold is used on all 200-229-262 cid (3.8 and 4.3L) Chevrolet V6 engines. This manifold is designed to use the following Holley carburetors: 390 CFM; 500 CFM; or 600 CFM, depending on your engine requirements. Technical Notes: This manifold does not use an EGR valve. Check manifold and carburetor-to-hood clearance before installation. This manifold will not fit 18 head.