Rear-end swap / driveshaft question.

So I'm bagging a 91 extended cab for a buddy on Tahoe wheels and we swapped to a 84 rear-end since it's narrower. When I got the rear-end I got the end off the 84 shaft as well but the 84 shaft is alot bigger in diameter than the 91's so I cant just get hte 84 end put in the 91 shaft. First thought was to make a plate with both patterns on it to go between the 91 shaft and the 84 snout, but (Finally, here's the damn question,) does anybody know if I can put the 91's snout on the 84 differential? Anybody done it? They both come off but are the splines the same? Thought I'd ask before I wasted an hour or so pulling them only for it not to work.

I'm curious to find out as well. does the old rx7 lsd snout fit in the pre housing?

I put a Toy rear end in my truck, and the Toy driveshaft is smaller diameter also. I took it to a driveline shop and he just made a new driveline with my 700r4 input on one side, and the Toy diff end on the other.

That's what we usually do but if the ends will just swap I won't need to. Bump for the afternoon crowd.