While you are changing tires now, it might be worth considering going to tubeless. Many tire shops will not touch split rims now, no matter what the style. What is your wheel bolt pattern? If it is 5/10 on 7.25, tubeless rims are hard to find but out there. Started with first tubeless in late '50's, look on farm trucks. 9" tires will fit on those wheels, are the most readily available size. About 36" OD.

Ed

Last edited by EdPruss; 12/25/2017 1:22 PM.

'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.