Looking for opinions.

So here’s where I’m at with my car. I just finished the front end disc upgrade from drums. Full front end rebuild. The car is a 71 Scamp. This car will be seeing in the future a 440/727 combo.
Now in the meantime I need to sort out my rear end. It has the bulletproof 7 1/4 ;-) in it now. It’s got some amazing bearing noises coming from it at highway speed. So I’m thinking to get the 8 3/4 going now. Dr.Diff has some LBP axels on for 295 a pair. Stock length. Go to either the 10 or 11 inch drum and slap it in with the 353 sure grip pig I have sitting here. I’m in talks for a custom length shaft to get me through. Any one do this before? Will drivability be crap? Slant six/904/8 3/4 with 353’s This will also help with a beauty set of rims I’m eyeing.
What do you guys think?

* Is there factory shafts available for this application? Was this set up an option?