I quick run down of what I went through:
Swapped in the v8, v8 t-5, and 8.8
1-Electrical; I had to extend my alt wires cause its on the driver side on the 4 cyl in order to not have to swap the whole head light harness, I had to find a 90 and up eec harness and comp, I also changed the tach and that was it to make it work, I did do a 3g alt up grade and 140 sped but electric fans and under drive pulleys dictated that and the sped is cause I would peg the 85 mph in a hurry.
2-Fuel; the entire fuel line from the tank to the engine bay, the stock fuel pump has worked fine for me
3-Brakes; I used the hard lines on the 7.5 and the splitter box for them, my 88 rotors would not fit on the 4cyl rotors and the 88 spindles would not fit with the 4 cyl struts and 90 and up struts have a diff bolt patern in the strut tower so I just ran 4 cyl brakes till I did the 5 lug conversion a couple weeks later
4-Clutch; I had to get the v8 cable, I still have the 4 cyl quadrant, I tried the parts store to see if there was a diff and finding none I left it
5-Exhaust, I simply pulled my off road x pipe out of the 88 and put it in the 4 cyl car and it fit fine just need the exhaust hanger on the pass side just in front of the fuel tank. I used my 88 cross member but if I remember correctly the later model foxs all had the double hump crossmember thats needed for v8 apps
6-Random; The throttle cable needs to be changed as well as the cruise cable or unit, I haven't tried to see if I can change cruise con cables or not. And I used the v8 drive shaft, I'm still running 4cyl springs and my car doesn't sit all that low but I am going to swap the sway bar in the front, and the v8 bolted in with the 4cyl k mem.
Hope any of this helps, it was kinda a pain but it wasn't too bad