I parted out two '40 trucks last week and can send you photos of the trucks before and after. One was a 1/2 ton and the other was a 3/4 ton.
The frames are visibly different. The 1/2 ton frame is actually wider than the 3/4 ton from the cab on back. As was mentioned earlier the rear axle on the 3/4 ton will have duplicate sets of leaf springs, one on top, and the larger longer set below.
Doug
