hello all I have a 77 f250 4x4, and a 78 2wd crew cab, that I want to do a conversion to a crew cab 4x4 long bed, what I need to know is are the front cab mounts in the same location ie width and spacing=cut the frame aft of the fwd cab mounts, make all measurements and graft in the section of the crewcab frame I need to convert this=seems all I have to do is

1) if measurements at front cab mount are the same
2) cut frame aft of fwd cab mount
3) graft in parts of the frame rails from the crewcab to facilitate the conversion to a crewcab longbed 4x4=I was told that the frame width is different , I highboy width on the crew