the shorter 4 speed with a tail intended for a bolt on "yoke" is the reason a center bearing is used with it, and the rear shaft for the 4 speed is shorter than the one with a 3 speed, you'll have a lot of changes to do to put in a 4 speed, if you even have the correct 4 speed for 58, and if the truck originally had a 4 speed, those items were changed [scrapped] to install a 3 speed
Bill
