What year is your pickup? Makes a difference on the driveshaft.

The cab and front sheet metal are common between the 1/2 & 3/4ton trucks. Beds are different lengths in the AD series. Frames are the same width, but the cross section of the frame is bigger with thicker metal on the 3/4 ton. We used to have a guy here who used 3/4 ton frames to make 1/2 ton trucks, maybe Luke or someone can recall what he did. If you have an AD truck, the frame swap to a later model is a lot of work, the later models had a wider frame.

Fred
52 3600
69 C-10