I found a place in Michigan to make new king pin bushings to fit both diameters so didn’t have to make any intermediate steps, $60. for 5(I made a spare) so I could fit the 3500 HD knuckles directly on the early(‘55 GMC) axle.
You didn’t say if your truck is a Chevy or GMC, I found a set of factory GMC, ‘42-‘47.2 wide front fenders to fit one of my trucks so the tires will not stick out from the front fenders.
I’m going to use 19.5’s on my ‘55 since tubeless 22.5’s are getting hard to find.
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.
