aluminum 4-speed tail housing

Autoxcuda, you could be correct on all the tail housings being the same. I didn't disassemble
the 76 feather duster overdrive transmission to check bushing or seal diameters. I do know it does use the smaller output spline like the 904 trans. I suppose it is possible I had the correct tail housing all along.
If anyone knows if the larger spline (727) main shaft could or couldn't be installed in place of the smaller (904) splined main shaft please chime in.
I have had this 76 all aluminum trans in my shed for 25 years and didn't know it had
the smaller output spline till I dug it out to use just the tail housing on a 18 spline build.
Seen they took a different slip yoke and found a different tail housing for my build that was removed from a trans with the larger output.