Frank,
Someone will correct me, if I am wrong; but, if you do not have a reamer and a hydraulic press, you should take the axle off the truck and bring the axle and spindles to a machine shop (that has experience with fitting king pins).
1. The axle will have to be reamed (drilled and reamed at a specific angle) for the over-sized outer-diameter of the king pin.
2. The spindle bushings will have to be pressed into the spindles
3. The holes in the spindle bushings will have to be reamed to the size of the king pins.
4. Also, you might as well have the shop install the king pins, shims, and bearings (and grease the assembly).
1/2 ton bushings do not need to be reamed and the bushings are a looser fit into the spindles than on the larger trucks. However, the axle on a 1/2 ton would still have to be reamed (drilled & reamed?) for an over-sized king pin.
Tim
