RHS™ Pro Action™ 200cc cylinder heads are the perfect street performance head for medium-displacement Small Block Chevrolet engines. Ideal for 327 to 350 CID street/strip engines, Pro Action™ 200cc cylinder heads are the hot ticket to making up to 400+ flywheel horsepower. With superb finished quality and a long list of desirable standard features -including top-quality COMP Cams® components in fully assembled models, Pro Action™ 200cc cylinder heads deliver maximum value for your performance dollar.