Not impossible at all. You want to really do it? Forget about the computer system. I own a 99 V6. I purchased a new tubular K-Member, carb, carb intake. Forget the OBD. I purchased a C4 tranny, torque convertor, and the proper bellhousing. I swapped out the 7.5 rear already for the 8.8 out of my doner car. Yes you have to space out the hubs on a 99 because the 7.5 on a 99 is 2 in wider on the tubes compared to the 95 8.8in rear. I purchased a Holley fuel pump that takes care of the fuel system when I get to this point. I also just purchased an old school Duraspark II ignition module and a distributor from a vacuum advanced 85 Mustang. Its easy. Only gauges that I need I purchased from Autometer. My springs were from the doner also, but they were already BBK lowering springs I had put on that 95. SO I am driving on a lowered 99 at least with an 8.8 and 3.73's. I even swapped out the bucket seats, backseat, and the leather steering wheel. I just drop the motor in and wire it up. One fuel line and few wires for the gauges, charging system, ignition system, and I am free from all the crap you guys have using your computers. OH and the refreshed GT-40 P heads from an Explorer are going to help out also. I rebuilt the doner cars engine 5,000 miles ago so its was ready to go. E CAM, .030 over bore, roller rockers, etc and lots of TLC until a deer took the car out. I was going to purchase a 94-98 V6 and do the swap since they are go much easier to find and cheaper for the wallet. I saw a red 00 Cobra R with the nice front valance and high spoiler on the rear and I said I am now going to get a 99-04 V6 instead. I can just clone a Cobra R. As far as I know no one has done this swap in a 99 and I plan on bringing back the 5.0 in it VERY soon, I have everything I need just sitting there, but I need to get relocated to a new location for my work and cant risk tearing down my only transportion. Swapping out rears, springs and seats is one thing, but not the K-Member and engine yet. BTW QA1 K-member.