This converter is built for use with the SPD 37 spline soild input shaft ONLY. It includes the needed SPD turbine hub, impeller hub, and inner sprag race. New billet front cover, new billet lock-up piston and three times the friction area over stock make this one of the toughest converters available. All internals are reinforced with tig welding or furnace brazing and supported by torrington bearings for reduced friction. This converter is competition ready with stall speeds tailored to your specific applications.