Currently started a new mustang project. Took a little time off from my fox. I purchased a 1997 mustang 3.8 and had a spare 4.6 motor and a whole donor car that a buddy of mine wrecked a while back. Anyways I just wanted to share and show everyone my progress and how to do this VERY difficult swap. I am currently about halfway through. First off. You need to pull the v6 motor and wiring harness and transmission. (Best to do them both at the same time) after you get that pos out of the way you will need to pull off the passenger fender and go inside under the passenger side dash and pull the kick panel off and the computer out. Then pull the wiring out outside the car. (Also a pain). You will need a new computer and wiring harness for a v8 car. Also you will need a new v8 gauge cluster. Some say you need a whole new dash, but I would argue against that. Next you will need a new hydro boost brake system out of the v8 car. The v6 brake booster is too large for the v8 motor. To swap over the brake system you will need to change out the power steering rack and pinion also. If you were going to change from auto to manual now would be the best time to do it. Pull out the steering column (5 bolts and some wiring I believe.) and then just unbolt the pedal assembly and reinstall the new one and run your clutch cable as you are doing so. 5 bolts. And some wiring and spring loaded assemblies. Pretty straight forward. It was pretty easy for me considering I had my dash out but it's not too bad. This is as far as I got. I will keep updating and show pictures as I go along. I know a lot of people have attempted this swap and there are always people that tell you not to but if you have to recourses and are mechanically inclined I say the hell with them. I will keep you posted. (Sorry for the disorganization).
You will need tons of different parts so buying them individually you will have a small fortune in it. So the best thing to do is find a donor car with everything you will need.
YOU WILL NEED
Motor mounts
Transmission crossmember if you are changing from auto to manual.
Rear end- optional, some say you can beat on the 7.5 rear for a while.
Driveshaft
Exhaust
Wiring harness
ECU computer- under passenger side dash
Gauge cluster
Fuel pump
Brake hydro booster
Radiator and fan
Rack and pinion
I may be forgetting some things. I will keep updating. If anyone has any specific questions shoot me a message.