These valve covers are die-cast from high-quality 383-3 aluminum alloy and then given a durable powder-coated wrinkled finish. They also feature cadmium plating on the oil filler tube to help prevent against corrosion, a re-engineered baffle configuration to work with high-lift camshafts, and the ability to work with most roller rockers. Also included is a new PCV grommet and spark plug wire brackets. Will not fit EFI cars.