1987 Mustang 4 cylinder to 8 cylinder engine swap

[jules82]

I have a 87 4 cyl convertiable i want to put a 89 5.0 in. I have the complete wiring harness from the 89 car witch was wrecked. can i use that harness in the 87 or do i go old school carb. Im going to do this project with my 18 year old son.

[mustang585]

If you have to computer too for the 89 I'd go that route cause you can convert to MAF. I think 89 is the only year you can use on 87 88 to convert to MAF cause there's no air bags. Its better for tuning.

[KingFlirt1]

i think carb is way less pain in the ass to deal with. IMO

[85beast]

Id go with a carb on that just harder in the cold.

[NJ Chick]

Hey there, welcome to the club! Sounds like a cool project. Tell us a little more about yourself and post some pics of your '87!

[jules82]

Thanks will a 88 computer work? Im putting a 347 in my 82 next week i can use my maifold and 2 baral go for my 17 year old

[tattoodave]

good luck, looks like it's a killer upgrade you got going...

[98blackgt]

wrong place to post

[Cobra Jet]

You will need (or use) the entire engine harness from a 5.0, of which will go through the firewall on the passenger side to where the EEC is located.

You will not need to do anything w/ the dash or remainder of the body harness for performing the swap.

Stay EFI - there's no need to "Carb it" if you already have the EFI stuff, including the EEC and engine harness.

The swap is not hard at all.

Remove the original EEC from the passenger side kick panel. Remove the entire existing engine harness for the 2.3. Once the 2.3 is removed, install the 5.0 (you will need the 5.0 engine mounts and they will bolt right to the existing K-member w/o any issues). Lay the 5.0 engine harness in the engine bay, start hooking up to the engine, etc. Fish the main connector to the EEC through the firewall to the pass. kick panel. Hook up the EEC.

I'm making it sound much easier, but in all honesty, it's not that hard of a swap and pretty much everything falls into place as you go.

If the car is a 5 spd - the 2.3 T5 will not be suitable for use w/ the 5.0, it's best to get a true 5.0 T5 tranny. Some folks have used the 2.3 IF you're not going to abuse it, but, it will not last behind the 5.0 for long...

You also may need to upgrade the 2.3's rear as well, IIRC, they still have the 7.5 rear as opposed to the 5.0 8.8 rear... again, a very easy swap and it's basically plug-n-play.

[greenscobie86]

Good info! ^^^

Makes me want to buy a 4cyl Notch and attempt this, but with a mod motor