84 cab on a 69 frame, anyone done something like this?

[72timemachine]

I have a 1969, Chevy c30 dually (utility bed) powered by a 350 with a 400 trans, I also have a 1984 GMC 1 ton dually crew cab (8 ft bed) 6.2 diesel with a 400 trans and gear vendor but the frame is bad. My 69 is rotted beyond repair but has a good frame.

Has anyone done this and know if I am going have any major problems? While I expect some hang-up if it is too much trouble I will pass. I am keeping everything stock if possible.

Thank you ahead of time for any advice.