What are you having trouble with? The k-member is the same so you will need 5.0 motor mounts to set it in there, you will also need to chang trans. crossover if it was automatic. Is it going to be efi or carb? Let me know.
I did this to mine...I had a donor car that made it easy...a lot of work but it is straight forward. You can use your stock dash and body harness. Get the harness from the computer to the engine, the injector harness....you will also need the headlight harness. The alternator plugs are part of it and they are on the drivers side on the 4cyl and the passenger side on the 5.0L.
What year are the two cars...if the gap is too large, I think the fuel pump relays are in different locations.
I am doing a conversion as well, so th K members are the same. ours is going to be carbed and we do have a donor both 90's. So I am assuming I do not need a EFI harness because it is going to be carbed?
What are you having trouble with? The k-member is the same so you will need 5.0 motor mounts to set it in there, you will also need to chang trans. crossover if it was automatic. Is it going to be efi or carb? Let me know.
I'm having trouble with some of the plugs not matching each other. I'm doing all this myself. No man has helped me. It's been a bitch. I took a '90 GT and put the motor tranny driveshaft and engine harness into a '92 4cyl notch. I hope everything works. It's been pretty overwhelming for me. Go to www.myspace.com/hotassgirlinamustang.com and go to my pics and there is a pic of the notch on it.
you will have to use the 5.0 computer and harness and the plugs under the battery tray will have to be switched for the alt. or you can lenghten your alt. wires by soldering in sections of wire all of the lighting wires will remain the same are you using a mass air harness(sorry about the punctuation thats how i roll)
The 90 model EFI/engine main harness is an odd duck. It is not compatible with other model Mustangs. That means your 92 harness is going to have some connections that are on the wrong place. The 92 EFI/engine main harness may be compatible with a 90 model Mustang with some interesting rework.
There are two plugs on the 90 model body main harness that do not mate up with any of the plugs on the other year EFI/Engine main wiring harnesses. Unfortunately I do not have any information as to what the two odd plugs do. I suspect that they may be for the air bag sensors.
At the top of the 5.0 Tech forum is the sticky "Useful Technical Thread" index. In it are tech writeups on a number of things like the 2.3 to 5.0 conversion.