If gear ratios are not a problem (the slow one you have) then how about just some 8R19.5 tires and new 19.5" wheels?

What is the plan with the truck, what will you do with it?

You may look at some E350 full floating Dana 60 rear axles, but I think they will be wider than what you have.

Grigg


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-