It's all going to depend on the rims you get. Measure the setback, distance from the flange on the back to the drum face surface. Compare that with your existing wheels. Then check the clearance of your existing tire to the frame and measure the section width of both tires. With all of that you can figure if the new wheel/tire will clear the frame and the fender. One more area of concern is the wheel to tie rod end clearance if your tie rods are on the back side of the front axle, I can't recall if it is on the 55.1.
As far as the tire height, it is not a problem unless you have lowered the truck. I recently put 7.50R16's on my 3/4 ton, there is only one inch clearance to the frame. Tight, but it will be set out more when I swap rear ends.
