Original question has been lost due to safety concerns. Warning: Opinion! Yes, tires are different from the old ones. But, not too different. Truck wheels, and truck tires are stiffer and heavier than car wheels and car tires. The load issues with old wheels and radial tires will depend on the condition of the wheel. Nothing has changed about that. Old wheels with lots of deep pits, or cracks remain suspect. Air leaks around rivets? Well, that was not an issue with tube type tires. If you have wheels that are in good shape(no cracks, loose rivets, or dents) then consider sealing the rivets. Are you gonna use a truck tire? I have and no problems. I do look for issues(wheels are over 60 years old). But so far no issues. Sealing the rivets: This has worked for me, heat the wheel around the rivets(a heat gun or a hair dryer will do the job). Make the area warm, not so warm it burns you but nice and warm. Mix an epoxy glue as the package says and apply. I use a popscicle stik(kind of fun to get the popscikle for my efforts) The epoxy will melt and flow into the leaky spot just fine. Let it set and cool. Then paint, coat or whatever you choose. Disclaimer time: If the "Radial tire/old wheel" issue is a concern for you. Get some new replacement wheels. Vendors should be willing to tell you if their wheels meet the current DOT standards. The epoxy trick just helps "seal" the wheel against air leaks.If you want "car" tires, then use replacement wheels.Skinny 6 ply pizza cutter truck tires seem to be OK. So far at least. I would not put a "wide" performance tire on any way. That seems to me at the very least, to be asking for trouble.