8 3/4 rear

You can use the 8 1/4” backing plates and brake set up on the 8 3/4” for the easier to get parts and works with the large bolt patern. If you use green bearings you will have to take the thrust button out the center section for large bolt pattern after market axles to seat all the way. Get everything you need off Dr. Diff and you can also call him and he will tell you everything you need to know. Really nice guy.