I have a M923A0 With 16.00r20 on it, with HEMTT rims. The rims provide approx. 2.5" more negative backspacing on the front axle, which stops the rubbing issues when in full lock-to-lock steering. With regular 5 ton combat rims, the left steer tire WILL rub the pitman arm. 5 ton combat rims would probably work better on the back, because they are lighter and would reduce rotating mass.
At first I was apprehensive of the 16.00's because of the change they make in the final drive ratio, but after having them on my truck for a while, I like them, and would convert another truck over to 16.00's if given the chance.
The negatives to them is that they are heavy, and HEMTT rims are heavier also, along with a heavier run flat. When going up a hill with a strong headwind, the bigger tires do affect the truck's ability maintain road speed. Use your shifter to control up shifts and leave the shifter a gear low when going slower or in hilly terrain to keep the transmission from gear hunting as much. Your speedometer will be approx. 11 mph slow when using 16.00's on an A0 truck, and will be approx. 5 mph slow on a A1 or A2 truck when using the correct adapter box that was installed with 14.00s.
I believe the best place to correct the performance issues is inside the transfer case, via changing out the overdrive gearing with something closer to direct drive 1:1 at the output shafts. This will be much cheaper and exponentially easier than regearing 3 axles.
