Apache, I just picked up a complete box at a swap meet. It came off a 67-72 series stepside. Once I got it home, I measured everything carefully and I am happy to say that the sides, front and tailgate are the same sizes. The holes for the fenders ARE different (as stated earlier), the cross braces under the bed are really close, but just 2 of the mounting supports will need to be drilled out and relocated outward by a few inches to mate up with my 57 short step side frame. With the cost of the aftermarket metal (and sometimes less than desireable fitment) I try to keep my truck all Chevy. Hope this helps!
Dano
