The likely axle swaps with same bolt pattern and better gears are Dana 70HD and 80 from GM 3500HD and P30 or similar chassis.
They all have disc brakes, and a vehicle with rear disc should also have front disc.

I have the 70HD (from an RV) in my 2 ton, and 22.5” wheels.

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-