So it has came to the point where my stock 3A is getting very teritorial. By that, I mean that it likes to really mark its territory by leaking oil all over the place from the transmission/t-case.

I was really hoping to get to rebuilding them this winter, but other projects for the wife got in my way.
Here is my question. I also have in my possesion a 1947 Willys truck that I picked up last fall. Before anyone starts to feel too much envy, let me assure you, this thing is RUFF. Multiple Bubbas in the past have used and abused this thing. My plan was to put a SBC in it and have a rat rod daily driver......... However, the reason I bought it originally was it still has the original motor, transmission, t-case and differentials (even the clamshell Timken rear diff) and I wanted spares for my 3A.
Will the trans/t-case in the truck be a direct swap for the 3A? I don't think there are any differences, but I wanted to double check. I am thinking about pulling the trans-t/case out of the truck and rebuilding it while I still drive the 3A around. That way, I can take my time on each of them and not be forced to hurry up and get the 3a back on the road.
Anything I need to check?