98gt swaping for the 03 mach1 dohc help

I blow up my 98 gt not a good thing I know . I didn’t just want a stock sohc to put back in so after looking and looking if I was to build a new eigen I was better off to get the 03 mach 1 crate from ford racing . I called ford racing and ask what all would I have to chang they say new fuel regulator and use my 98 gt harness and cut in for the cole on plug no big deal so I go and drop the $$$$ for it I know it would be ok b/c ford racing said so lol RIGHT !!!!!!!! well no ther is so much more . so now im looking for the harness to the cpu or maybe if u have done this swap u could get a hold of me and tell some of the stuff u did