I wanted to share my experience with changing out the original wheels and tires on my 1950 Chevy COE, model 5700. It came with 8.25x20 tires and the original Firestone RH-5 two piece split rims, the true "widow makers". I had Stockton wheels modify modern 22.5" rims with the proper bolt pattern and hub diameter. I spoke with Frank, the owner, who had done this modification before. The tires I got are Goodyear (I just couldn't put Chinese tires on this truck) 9R22.5 and the diameter is within 0.1" of the original 8.25x20 tube tires. I am really pleased with how this came out. My goal with the truck is to do a frame off restoration and maintain originality as much as possible. After researching the wheel situation, I was just too concerned to keep the originals. When I got the truck home to AZ from MN, I found some of the tires had only 5 lbs of pressure in them. I had to fill them up and offered up my left arm and kept the rest of my body away as I filled them up to a nominal 40 lbs. I am not totally freaked out about split rims, my Diamond T has them in excellent condition but they are the 2 piece with the locking ring. The appearance of the new tire/wheel combination is so similar to the originals, that it was difficult to see the difference even when they were side by side. They have the same contours and 5 handholds, just like the originals. The new wheels have plenty of clearance for the large rear drums, which is why you cannot go with 19.5" wheels.
I understand the cost may prevent some for going done this path. The wheels cost $275 each to fabricate and I did not get the cheapest tires and remember the multiplier is 7 (I got an extra for that spare carrier that came with the truck). In the end, it cost me more than the truck did, but I know I won't have a safety problem when one of my sons or someone else takes ownership of the truck.
I have to thank this site, and in particular Grigg for a great tech tip, in educating me about this topic. So if someone is contemplating this change, I would recommend it.
