New Guy, If what you have is 5/10 on 7.25", late '50's first tubeless tires had 9 x 22.5 tires, mostly found on farm trucks that should work on your truck. The rims are sort of narrow, but mount a 9" tire OK. If that is what would work for you, don't bother calling around wrecking yards, they won't know what you are talking about, and if they think they are rare(they are) , they will charge too much. Look around junk piles, abandoned scrap piles, many farmers and ranchers have those. Ed

'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.