The only safe way to maximize compression; the valve reliefs in the piston are purposely convex and match the geometry of the dishes in the valves, Conversion to Black Diamondﾙ stainless steel valves offers up to twice the life of the stock titanium valves, No loss in performance, Kit includes: piston, rings, clip and pin, Cometic top end gasket kit, Black Diamond engine valves (standard size) and dual spring titanium retainer springs (.395" lift intake, .0370" lift exhaust), Made in the U.S.A., Pistons, rings, valves and pin clips in this kit are designed to work as a system, they are NOT COMPATIBLE with the OEM components and should ONLY be used as a kit.