Willy,
I assume you want to move ALL of the sheet metal (cab and front clip) from one frame to the other...
Both trucks should have the same front axle with number 3711405 forged into them. So the measurements would be the same.
The parts book says 55 thru 57 share the same frame and 58/59 share the same. I've never had one of each to compart side by side, but if I did, I'd be comfirming the frame drop between the axle and bumper were the same. Any other issues can be worked out, like hole locations for the core support.
Mike B
