I did the opposite thing on an SM420. From torque tube to drive shaft. I was real easy. 4 four bolt change over. The seals fit and everything. Tail shaft did not change. I suspect the same will be true with the 3 speed. Just get the tail peice off the truck trany. I think when they went to the drive shaft in 55 they used the same tranny and just changed the tail piece. The tranmissions are identical otherwise. I had the advantage of finding a transmission guru who knew exactly what I wanted and had one in pile out back.
Where did all those guys go?
Last edited by Tacoman; 04/10/2014 12:44 AM. Reason: poor writing skills
