Good to hear you talked to John.
Did he have a rear bearing retainer cover, used with the torque tube drive line?
Did he say that the u-joint assembly for the 3/4 ton is different than the 1/2 ton u-joint assembly?
I'll hunt around on Craigslist to maybe find one.
I found that you are better off looking for the entire SM420 transmission, because most of the time
they still have the 1/2 ton ball housing and u-joint assembly attached.