Springs Valve Std Kz1000 40-0449Valve Spring KitExtensive R&D on all applications to provide high performance components that last longer than OEM Super clean silicon wire used in valve springs is ground, not shaved, and X rayed at regular intervals to check for flaws Keepers not included; use OEM keepers and bases, as noted Valves and guides are sold each; spring kits come complete for one motor and include instructions All components made in the U. S. A.