72 3/4 4x4 tranny??

[cmabolt]

Hi all, I am trying to figure out what trans I have in my 72 cheyenne.
Its a 3/4 ton 4x4 4spd with granny.

Does anybody know what the options were with these trucks. It is bone stock
with heavy duty everything as it was used a a camper most of it's life.

350 small block, ho52 rear, dana44 front

any help or references would be great!

Thanks