92Flareside

I have a '92 150 that currently has the 5.0L in it. i just built a 5.8L for it, but now i need all the parts to make it run correctly in the truck. Research tells me that i need a new computer and wiring harness, but i cant seem to find anyone that makes the correct harness (even painless doesnt carry the right one...) The part #'s of the harness's that i need are F2TZ12A581C and F2TZ12A690AA. If you know anywhere that has them available (new, N.O.S., or refurbished) or if any of you have one lying around in your garage but no longer need (as long as its complete and in good working order) im willing to take it off your hands for a fair price. Also, are there any other potential problems any of you can foresee me facing? Thanks for any help!