Reply to nyoffroad - I had the 20" rims built way back in 1985, 28 years ago, and installed on a brand new 1985 K30 single rear wheel pickup. Back then, 20" rims on pickups were unheard of. The only way to have 20" tires on a pickup was to build the rims to accommodate them. So I hired my machine-shop buddy to fabricate five (5) 20" rims. We purchased standard Firestone 20" x 8.25 split rims from a wheel supplier and his machine shop fabricated and installed the wheel centers. The custom fabricated centers were milled from 1/2" cold rolled steel on a giant Bridgeport milling machine, and mig-welded in place on a dead-flat granite fabrication table. I wish I had taken pictures of the process. The wheels were fabricated in such a way as to orient the lock rim towards the inside, so that in case of separation from the rim in an adverse condition, such as getting against a rock, the lock rim would fly off to the inside and not cause bodily harm to anyone standing nearby. The custom centers were welded exactly in the middle of the 8.25 Firestone wheels, not because of any rocket-science calculation, but instead through complete ignorance to where they SHOULD be positioned. As it turned out, this was a stroke of blind luck as the wheels and tires turn perfectly without hitting any chassis component.
I have been asked many times over the years about the durability and road worthiness of the wheels. I ran them for 10 years and 225,000 miles on my 1985 K30 civi truck with excellent performance. Then in 2010 when I acquired my M1028, I resolved to utilize them once again with 11.00/20 tires for a truly unique military application.
On my M1028, as well as on my original 1985 K30, I had to overcome balancing issues. Back in 1985, on my K30 civi, I simply used lead weights to balance the wheel/tire assembly because that's all there was available. I am sure you read in my rebuild thread that, on my M1028, I initially utilized Balance Masters, which is the method of balancing HMMWV wheels in the military. While these Balance Masters worked OK, I was still experiencing a few bumps at low speeds. So I removed the Balance Masters and installed 15 ounces of Dyna Beads in each tube. These are perfectly round dry ceramic beads which are installed through the valve stems and which automatically balance the entire wheel assembly including hub. After installing these in each tire, my M1028 rolls smoother than my wife's car. It is truly a pleasure to drive.
My M1028 rolls smooth with absolutely no vibration, tracks true, and turns on a dime. The completely rebuilt Dana 60 front end has no evidence of the "death wobble", and the cross-over steering is positive and does not need hydraulic assist. I would not hesitate to drive my truck across country if necessary, and would enjoy every minute of the ride.
Hope this helps.