One-piece stainless-steel, stellite-tipped valves impregnated by a special nitrided process with .002 depth and .0002 surface buildup to improve wear properties and reduce friction. This process provides resistance to corrosion; wears superior to hard chromium and electrolysis nickel-plating. Lightweight with profiles that provide excellent flow characteristics. Compatible with leaded and unleaded fuels and can be run in cast iron- and bronze-type guides at close tolerances for maximum oil control and heat dissipation. Made in the USA Head Diameter - 1.900in. Stem Diameter - 7mm/0.2760in. Tulip - 28 deg. Length - 4.500in.