The Stovebolt Site Forums The Parking Lot Big Bolts tire & wheel swap

I was in the salvage (not junk) yard today getting parts for my trucks. I was checking the tires on some of the big trucks. There was this '66 5000? Chevy with 8.25"x20" tires. The wheels were 5 lug front & 10 lug rear. I didn't have a tape measure, but the patterns look to be the same except the studs look bigger. The tires are in great shape with deep tread & they want $50 for each wheel tire combo. If the wheels won't fit, it would be worth it to swap the tires onto the old rims. The question is: How much clearance should there be between the two tires on a dually? There shouldn't be much flexing on such heavy tires. Or is it possible to get the studs off donor truck & drill out the holes on mine assuming same bolt pattern? I did this on my '62 Bel Air with no problems. I would get some later model 19.5" wheels, but they all seem to have small tires. Thanks.
Scott