You might want to try posting this question over at the H.A.M.B. website. Those guys do a lot of hotrod-type modifications that don't happen on this site very often. Be aware they're a raucous bunch- - - -bring a thick skin!
From the experience gained from 50+ years of building race cars and various other rigs with major sheet metal modifications, let me advise you to bring money- - - -lots of it!
My best friends are Sam, Eli, Bill, and Gene: