so the 76 up trannys are superposed to have a different angle on the output shaft and the planetary hub. i have a planetary set out of what is supoosed to be a 76 tranny but the planetary will slide right onto the 72 output shaft and seems to fit the same as the warn out 72 hub.

I remember reading about that way back in one of the Mopar mags. What I'd do until some who knows chimes in is I'd check out the spline/groove interface with em fitted together with a magnifying glass & see if you see a mismatch on the angles

The angle of the splines changed in '76 and again in '94. In some cases of mismatch the parts will go together but the fit will be loose (and weak) or they won't go together at all.

When in doubt, slide the planetary on the bare output shaft and shine a bright flashlight in from behind. If the spline angles are mismatched it'll be obvious when viewing the light shining through the front.

thanks guys, a buddy emailed me the mag artical. from the pictures its pretty obvious they are different and it looked like the early hub will slide on the 76 later shaft but not vise versa.

shining the light would for sure be better than trying to use a magnifying lens