351 in 99, ????'s
 

I'm slowly gathering parts for a wrecked 99 that I want to put a 351 in. My plans are to use a harness and computer from a 89-93, 95 front accessories, and a fox-swap oil pan. Will these work, if so can I tie in the stock 99 AC and lights. I would like to, but am not to worried about, keeping traction contol, can I do that with the 89 computer? Anyone have input on such a swap.

The 99 Saleen S351's came with a 351, so I'm sure it will work, but that's about all I can say.:(

You'll need to get the front crossmember from a '94 to '95 5.0L mustang and motor mounts and it will mount right up there. I don't know about the trans mount, but if you use a T5 you should be able to use the trans mount and if not i think you can use one out of a '94 or '95 maybe even an older fox body mustang. You will probably have to change the Air Conditioning a bit because of the different component locations, and again a '94, '95 5.0L would have the correct lines w/fixed orifice tube to and from the condensor and evaporator, a compressor that will bolt up and a suction accumilator/drier.
The lights should work as well. If you use the older style engine computer, the traction control won't work i believe it's multiplexed into the PCM, which would be removed. You'd probably have to use the ABS EEC-IV processor out of a '94 or '95 to have ABS operation since it's not multiplexed with the PCM, but i'm not sure if you can use the traction control because i think that's a newer option tied into the 4.6L's Powertrain control management system.
So basically, for your time, find a wrecked 5.0L '94 to '95 stang for the easiest swap parts with least fabrication/custom wiring. It's probably worth your time.
I hope this helps, good luck!