8 3/4

Hello I am looking to upgrade my rear end to the 8 3/4 was thinking of shortening a different body rear end and using a big bolt pattern. Will the brake assembly from a small bolt pattern work with the big bolt pattern axles or would I need to buy new brake assembly?
I don't think it will work, at least not without a whole lot of measuring and figuring. I made that mistake and had to fabricate 1/4 inch spacers to push my backing plates out out of the drums . Which made my splines that much shorter.... so I had to widen my thrust spacer. Thankfully, there was still enough spline left to engage my cone-clutches. Or something like that; it was a loooong time ago.