7 1/4 to 8 3/4 rear end swap info needed

To swap a 8-3/4 in place of a 7-1/4, you'll need shock plates. The 7-1/4 is to small and that is for every rear you try and use them on. New U-bolts would be a very good idea.
Then you'll need to shorten the drive shaft accordingly

Most 8-13/4's are small blot.