Originally posted by Kirk Higgins:
I am going to swap the axles
You say axles each time, but the dialog here has all been about the front axle and springs.
The rear might be a little more complicated.
The rear on a 3/4-ton is a bit different than that on a 1/2-ton. The rear has an open driveline, not the torque tube that the 1/2-tons had until '55. Also the 3/4-ton rear is mounted fixed and under the springs, while the 1/2-ton rear is pivot mounted on top of the springs.
The rear of the frame is parallel over the axle on your 3/4-ton, but not on a 1/2-ton. So not only are the springs on the sides of the frame instead of underneath, but the alignment of the springs is a little different.
All of this is why I'd suggest you look to put a later rear under the truck, at least a 1955, and that you be prepared to move the spring pads on the axle as you do so.
All this assuming you are planning to do the rear axle too...