Quality replacement valves lower priced than the Manley Severe Duty valves. Still offering a significant improvement over the OEM valve. Stainless steel construction with chrome plated stem and hardened tips. Excellent stock overhaul valve. Race Master valves are manufactured of stainless XH-426 for exhaust and stainless NK-842 for intake and offer great ultimate tensile strength combining superior quality at a competative price. Okay for stock or racing upto 8000 RPM. 66-84 Shovelhead (NU)