I have a similar setup to Grigg's in my '37 GMC. What wheel bolt pattern do you have now? If 5/10, then a D-70 or 80 come with that pattern. 22.5" tubeless wheels are available, however, hard to find. Fit and Look correct in the fenders.

You want about 3:1 final drive ratio if you wanted drive on the freeway, plan how to achieve that from the start.

Good luck.


'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.