Please check and make sure I'm correct.
1947 to 61 has the 8 lug hub behind the brake drum.
1962 to 72 has the 8 lug hub before the brake drum.
That's the reason the 62-72 conversion kit includes a very deep rotor.
I did not check the 3/4 ton axle lengths from 1947 to 72.
Eaton manufacturing ends in 1972.

"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."