Brake Question

You lost me. Are you saying the one you have is too wide? Or you have axles that don't fit the housing?

If you have a finished housing/ axles, is this something you can adjust with wheel backspace?

To put this another way, let's say you have a housing/ axles which go together, and can be made to work under the car

Brakes will only add a small amount to that. Disks are the thickest, maybe 5/16 of material per side.