Exhaust 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, Extends the life of the valve train and intake components by as much as 4x over the OEM titanium parts, Includes forged one-piece stainless steel intake valves, wound chrome-silicon heat-treated wire valve springs, ultra-light titanium retainers and hardened steel bases, Components are created using Finite Element Analysis (F.E.A.) software, as well as proprietary camshaft analysis and spring design software, Specifically designed and engineered for each application, Kits do not include valve stem seals unless called out in the application chart, Made in the USA