Chrysler built the transmissions for their intended usage. So that means a 383 didn't get as many clutches as a 440, etc.
The motorhome transmission would be worth rebuilding because it is pretty heavy duty. You'd actually open them both up and use the tailshaft and tailshaft housing from the regular 727 on the MH transmission.
I believe the tailshaft has to come out from the inside so now would be a perfect time to do that, while you're rebuilding it anyway.

Post the numbers stamped into the side of the pan rail and someone here will be able to tell you what they are.

R.