Found this 8.75 in my buddy's yard

What length axles did you use i may have a line on a set for a good price? Where did you get the backing plate and the rest of the internal parts from?
Did this years ago and don't remember the axle length. They are used OEM axles, my friend had a garage full of different axles at the time. Any BBP brake setup works, I would get 11x2 or 10x2.5 at the junkyard.