750629 Special Parts Required to Build 5 Into 4 Transmission Counte

This Jims transmission case is specifically engineered to allow the installation of a five-speed gearbox into four-speed Big Twin frames. Manufactured from 356-T6 aluminum and precision CNC machined, the case is designed for Shovelhead-style drivelines using a chain final drive. It accepts most standard five-speed bearings and seals from the 1985 to 1989 era. The assembly comes with the shifter shaft guide, shift lever adjustment screw, and all necessary studs and dowel pins pre-installed for a straightforward setup. While it retains the classic four-speed frame fitment, it provides the internal strength and gear options of a modern five-speed transmission. Note that this case is not compatible with factory belt-drive Sturgis models.