if your torque tube rear end has Bendix brakes, you may be good to go. The crash box transmission is about 2 inches shorter then the SM420. I would think that the SM420 would work with a 51 rear end (Bendix brakes) but would be to long for a 47 torque tube differential. Worth checking. Torque tubes come in a variety of lengths.
Last edited by Donf; 04/05/2020 3:21 PM.