It looks like you have 5/10 bolt wheel pattern, 5 on the front, 10 on the back, although all wheels have 10 mounting holes, so they fit front or back. That pattern has been on Dana 70 and 80 rear axles for a long time, so start looking for that pattern in wrecking yards. Get the associated front axle, some came with IFS while early ones had solid axles. Baby school buses are one good place.

The problem is wheels. 19.5’s are on all modern axles which look undernourished but are used by many. Late ‘50’s GM had 22.5s on the first tubeless wheels but are very hard to find and new ones are very expensive and have a long lead time. Look for farm trucks and school buses. Modern tires and associated wheels that are tubeless are designated by .5” dimensions, I e 19.5 or 22.5” while older tube type split rims are designated by even inch dimensions. Many tire shops will not deal with split rims.

Next best option unless you are very lucky in to use 20’s, however, late axles have a slightly larger hub diameter which must be bored out. This is a machine shop operation, not home backyard operation.

I’m sure others will chime in. Good luck.

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.