complete custom 8 3/4 rear and driveshaft?
For driveshaft's I use Action Machine
Action Machine Inc - Custom Driveshafts & CNC Machine Shop in Indiana. Great work and prices and real fast service. I just had a 3" aluminum driveshaft with 1350 yoke and u-joints built and shipped to me. Good for 800 hp. $443 shipped to my door.
What are you needing in the way of an 8-3/4? If it's just a housing I might be able to fix you up if you don't mind waiting 2-3 months until I'm caught up. PM me if you like