I would recommend you try some 8R19.5 tires.
You can either buy new wheels, or find some old ones, not to hard to find.

I assume you have dual wheels, either way, wheels are available.
Lug nuts should not be a problem. Ford used some big nuts with small holes and a large chamfer, perhaps they can be found in the right size, or you can make or modify some.

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-