As Ken stated, the transmission is the SM420 for both applications. No the U-joint is not the same. The 3/4 ton U-joint is heavier and is about impossible to find. No one is making a replacement for it and about the only way you will find one is if someone has some NOS on the shelf or a good junker.
Joe, if you have a four speed in the 1/2-ton already then why are you asking about the 3/4-ton??? All of the parts to rebuild the SM420 are avalable from Novak and all of the parts for the 1/2-ton U-joint and coupling are avalable from most of the vendors.
Denny Graham
Sandwich, IL
Last edited by Denny Graham; 04/22/2010 12:33 PM.
