GSC 30mm (+1mm) Exhaust Valve Set of 8When 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 software, 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