mike82fairmont

Wow, sounds like you have a nice car.
Yes, the '93 upper and lower control arms will swap easy, just make sure you have a set for the sway arm to bolt on. I would get some aftermarket arms if it is in your budget if you are going to put somme power to the rear.
The Stang H-pipe will work as well as most of the exhaust. The Stang exhaust is short between the mufflers and the rear axle. S you can use all Stang exhaust front to back end of the mufflers, splice a couple pipes in and conect the Stang exhaust tips.
Your lower A-arms are fine and will work with the spring up grade....though if you thought about switching to a five lug set up, then I would swap out the spindles, calpers, springs, sway bar, etc.... This will give you many more wheel options and bigger and better brakes.
As for the engine swap......what do you need or what are thing about doing? Also, have you checked out my web site for moer details on the engine swaps?
Let me know if you need more help!!
Later,
Stymeesmont