Twin Power is proud to offer a line of high quality USA made valve kits. Offered as Black Diamond Valve kits,valve kits include 4 stock size Black Diamond valves for each applicatio Black Diamond Stainless steel valves are impregnated by a special German process to a depth of .002", with a surface buildup of .0002". This Black Diamond process improves wear properties, reduces friction and provides resistance to corrosion. Valves are lightweight, strong, one-piece forgings with profiles that provide excellent flow characteristics. These kits are manufactured to original O.E.M. specs using premium modern materials, design protocols and manufacturing techniques. All components are high quality parts. Designed to have optimum fitment, allow maximum lift and maximum life. Resistant to high temperatures.