We did that on a 3rd gen truck that we sold about 3 years ago. We put a 3rd gen ExtraCab cab on a 1984 Shortbed Frame. Modifications were done to the back of the cab and the front of the bed was bobbed.
I'll have to see if I have any good pictures of it before we sold it when I get back home.
BigMike
Was there any body mount work needed to get the 3rd gen cab on the second gen frame?