Help identifying differential 65 Barracuda V8
I agree with all of the above. I would first get it running, moving under its own power, and stopping safely. Those brakes might not need more than just the wheel cylinders, a new master, and a good bleed. Do everything you can that’s free, and buy just the stuff you need. I’m sure the fuel system will be a focus as well. I was speaking to the rear end situation because you asked about changing yours out, but the crowd is right on, don’t change it unless it’s bad, I’m sure it’ll make at least a few trips, and maybe many more.
Just be rest assured, spirited driving IS in your future!