Kibblewhite Precision Nitrided Exhaust Valve - Oversize 20-20925One 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