Lightweight cast aluminum manifold features an open plenum to boost engine breathing and dramatically improve low-end torque and performance from 2,500 through 7,000+ RPM. Allows installation of larger standard-bore 4-bbl. carburetor (sold separately). Includes installation kit. Note: Not legal for sale or use in California on 1966 and later registered motor vehicles. This product is intended for off-road or racing use only and is not intended or applicable for highway use.