The F250 will be a thicker frame. If it was me I would find another F250 to do the swap. Yes being different is good but putting money into something then quiting because it was a bad decision is not. I'm all for this idea, I just think you will see that it will be a big project. Why not sell the F250 and buy a donor F150? I am in no way trying to crush your dreams as it sounds like a neat project. I would just hate to see someone give up after they sink money into something.
2009 Suzuki LTZ400 2004 Mach 1
1993 Acclaim 3.0 1992 F250 7.5L
1989 F250 7.3L 1986 Honda ATC
1983 Capri 5.8L