1957 DeSoto 8 3/4"

To clarify. This 65 cbody housing is flange with the 5 bolt holes? You’re using the correct backing plates and axles that came with it. If so, you shouldn’t need to change anything. Just but the chunk in.

Correct. 1965 C-body housing, 1965 C-body flanged axle shafts, 1957 DeSoto center section, I'll be converting it to disc brakes.