Changing rear end yoke

I've changed many a seal back there with nary a problem. I index the nuts tho, and put it back about where I found it. Swapping the yoke is a little different tho. The 741 has a history of having the pinion nut back off over the years, so torque it up right.
Early models, IIRC, had u-bolt retainers. You might find a pair of those. If you do, put a lil anti-seize on the shanks, so they don't rust solid over the years.