WHO HAS PUT A 5.0 SEFI WHERE A 3.8 CFI USED TO BE?

[nelzfoxes]

OK I've got a 1985 ltd station wagon squire with all the options. The donor car is my 1986 mustang gt convertible. The wagon is C5 auto and the gt is 5 speed manual. My plan is to leave the wagon auto. What I need are some specifics from someone who has done this already. Do tranny lines interfere with v8? I'm leaving c5 for now. How much wire splicing to get it done? Will the cruise control on the wagon work on the 5.0 which didn't have cruise? I've read on here that the dual pump system on wagon will work fine. True? I don't have evtm's for either car yet. I'm just trying to do as much research as possible so this goes as smooth as possible.

[mustangxtreme]

I can only answer to the C5. A 5.0 will bolt up to it. You will need to get a 164 tooth 50oz. flex plate. The transmission lines work fine. This is the current set up I have in my 83. What I don't have answers for are any of the wiring, cruise control, fuel system or shift/kick down linkage. Good luck.

[frink84]

the fuel pumps should support a efi 5.0, but due to their location, you cannot run dual exhaust. this can be remedied by modding a mustang tank/floorpan in the rear to fit, or making a hybrid hanger and using the mustang fuel pump in the ltd tank.

when my dad built his 2 5.0-swapped wagons, he swapped the entire harness/dash over, making the wiring a great deal easier (although a few wires had to be lengthened due to the length differences between a wagon and a mustang). never did hook up any cruise-control stuff.

84 ltd w/ 87/91 5.0/aod


79 fairmont w/ 86 5.0/5-speed

[FuturaGuy]

If you want to have dual exhausts, you can also get rid of the external fuel pump and replace the in-tank pump with an '87-'92 Camaro 350 pump. I used the Chevy pump when I converted my '79 Futura to EFI. Some guys have used Mustang pumps. The fuel pump conversion has been discussed in several places on this board.

Having an '85, you have an advantage since it's already set up for injection. You don't have to change the tank. If you go with the in-tank pump and get rid of the external pump, you'll have to fabricate some lines to connect the tank to the filter.

[nelzfoxes]

Thanx guys! I am so diggin this internet forum thing. Between FEP and Tacomaworld I have learned so much about the vehicles I own and how to modify them. Both sites have been immensely helpful.

[Ourobos]

Some bad info up there.. The 3.8 CFI only has the intank pump, you can run the 5.0 and dual exhaust, you need the 5.0 fuel lines anyways. I just put a 3.8/C5 CFI 86 Mustang to a 5.0/AOD SEFI. I swapped in a A9P computer, an 86 GT engine and driver side engine harness, and converted to mass air on the ECU harness. Was a pain, but runs and drives GREAT! EVERYTHING works (I've yet to charge the A/C).