Intake Valve Kit Stainless steel conversion kits include only what*s needed to convert your head to the long-life stainless steel Black Diamond intake valves, Extend the life of the valve train and intake components by as much as 4x over the OEM titanium parts, Valves are designed to not only life span over OEM, but also designed to flow and perform OEM components, Components are created using Finite Element Analysis (F.E.A.) software, as well as proprietary camshaft analysis and spring design software to ensure consistent performance and accurate designs, Specifically designed and engineered for each application, Made in the U.S.A.