8.25 Vs 8.75

Small bolt pattern axles will have a different bearing position to match the corresponding offset of the backing plate/brakes that came with them.

You can't mix parts between small and big bolt pattern axles. They need their corresponding brake assemblies.

Big bolt pattern 8 3/4" brake assemblies (B-body) will interchange with big bolt pattern 8 1/4" brake assemblies ('73+ A-body . They are the same size and backing plates have the same offset.

The drum register on the big bolt pattern axles is bigger also.