If things don't work out with the motorhome trans. www.wittrans.com sells used parts real cheap
In addition to the output shaft splines changing in 76 the pump and front clutch carrier changed in 71 to the wider bushing style. Can't say positively but the front carrier in the last picture looks like it has the 71 and up wider bushing. A much better design IMO
Yes everything is good. My trans is a 74. I have the pump and both clutch retainers reassembled. So far so good. I didnt switch the planets. It had the same as my trans. 3 pinion alum basket