3 to 4-speed conversion kit for 45inch Flathead

Will enable you to turn the stock 45inch 3-speed transmission into a 4-speed. 1 2 3 are smaller and 4th gear is identical to OEM ratio to get closer to the optimum RPM (Torque) at different speeds. Fits 3-speed 45inch (750cc) Side Valve models. 41-46 shift pattern. Can be used with later models when converted to footshift or the tankshift pattern is converted to 41-46 style. Note: The stock transmission side cover (kickstart cover) must be machined to accept the larger first (low) gear. Optionally a special 4-speed transmission side cover is separately available as 971591.