GSC 33mm (+1mm) Chrome Polished Exhaust Valve SINGLEWhen creating our new valve line we set out to create the best performance longest lasting valves available to the aftermarket. Using advanced 3D design and simulation programs we have created a stronger and higher flowing valve head design. We flow test prototype valve heads in the specific applications to make sure we have the highest flowing valve head available on the market today. With the materials used we have less valve distortion at the face