Fox T-Bird/Cougar Forums

Technical => Engine Swapping => Topic started by: Thunderhawk on December 16, 2007, 01:29:38 PM

Title: 3.8 - 5.0 swapout
Post by: Thunderhawk on December 16, 2007, 01:29:38 PM
I just recently bought a 1989 Mustang LX with a 5.0. I plan to use it for my 1986 T-Bird with a 3.8. I was told I could use the front end out of the LX to achieve an upgrade for the Bird. Has anyone had any experience with this swap? This is my first Ford venture. I have previously been a "Chevy Man". I look forward to this work, as the T-Bird is an awesome car. Its just been sitting in my garage for years now, awaiting some care. The 3.8 quit running some time back due to some electrical problems. I can't wait to get the swap done and get it on the road again. Hopefully, some of you guys can steer me away from potential problems I might encounter along the way. I look forward to your responses and thanks to all who help.
Title: 3.8 - 5.0 swapout
Post by: Haystack on December 16, 2007, 01:36:17 PM
check out coolcats.net in the tech section. It'll tell you all. Any questions come right on back and ask
Title: 3.8 - 5.0 swapout
Post by: vinnietbird on December 16, 2007, 01:43:06 PM
You'll need to swap the fuel lines,fuel pump,exhaust,and you'll need a wiring harness.The Mustang and T-Birds have different harnesses.I found that out this summer.You'll also need the Mustang computer.Do the Mass Air conversion while your at it (do it and get it over with).I can speak for myself and say that you need a 5.0 T-Bird or Cougar harness.You can swap the front suspension to the Bird for larger brakes,and I'd also swap the rear end from the Bird and use the Stang rear.better gears and it should be a Locker,although,I have seen a few stangs that didn't have a locker.Good luck.
Title: 3.8 - 5.0 swapout
Post by: TurboCoupe50 on December 16, 2007, 02:36:15 PM
Quote from: vinnietbird;193025
The Mustang and T-Birds have different harnesses.I found that out this summer.You'll also need the Mustang computer.Do the Mass Air conversion while your at it.



The '89 Stangs ARE Mass AIR... Harness can be used, just will take a bit of adapting... I made adapter harnesses from the original 2.3 engine & 5.0 body connectors... Also possible to re-pin the the harness so it will plug in without making adapters...

Basically if you are electrically challenged, it will be a tough swap... If you're good with wiring or have a buddy who is... Piece O cake...
Title: 3.8 - 5.0 swapout
Post by: vinnietbird on December 16, 2007, 03:43:08 PM
I had a Stang harness and it had a couple of different plugs than my Sport's harness,so,I sold the satng harness,and bought the conversion kit for Mass Air.I know the '89 is a Mass Air car,I meant do the swap on the Bird.I've seen a lot of folks who keep the speed density,which,there is nothing wrong with.I didn't want to do a lot of work on converting the harness because I hate doing that kind of electrical work.Foglights,stereo,no problem.My computer harness,that makes me nervous.
Title: 3.8 - 5.0 swapout
Post by: Beau on December 16, 2007, 03:58:08 PM
You'll also need V8 mounts/brackets for a Cougar/Tbird, as the Stang mounts won't work. On the '86-88 K-member there seems to be a bit of confusion on the mounts, which ARE available at better parts stores, versus the brackets, which are NOT available from any parts store.
However, ChuckW has saved our bacon with his custom mounts (http://"http://www.foxtbirdcougarforums.com/showthread.php?t=12926").
Or you can look for those rare brackets in junkyards, too, although the yards I've looked in, the brackets are always gone from those cars, usually the first thing taken, I think.

Good luck, and this is the place to come to about Fox Tbird/Cougars!
Title: 3.8 - 5.0 swapout
Post by: vinnietbird on December 16, 2007, 07:51:38 PM
I just happen to have a set of those rare brackets,although one would have to go to the parts store for new insulators.They don't cost too much.
Title: 3.8 - 5.0 swapout
Post by: dominator on December 16, 2007, 11:55:46 PM
It's about time someone used a stang as a doner for a bird instead of the other way around!
Title: 3.8 - 5.0 swapout
Post by: Thunderhawk on December 23, 2007, 10:45:59 AM
Hopefully, I'll get this project started after the first of the new year, I have to get some working room in the garage. I'll make sure to document with pics and try to post as progress is made. Look forward to all your helpful hints and comments throughout the entire job.
Title: 3.8 - 5.0 swapout
Post by: Kitz Kat on December 24, 2007, 07:38:17 AM
The v6 engine mounts should be the same as the 5.0's.
But being old should be replaced anyway.
Title: 3.8 - 5.0 swapout
Post by: Thunderhawk on January 01, 2008, 11:40:18 AM
Turbocoupe50, what kind of adapters did you have to make? Re-pinning the harness, you wouldn't have a listing of needed changes would you? I haven't yet started this, just trying to get all ducks in a row to save time and trouble.......
Title: 3.8 - 5.0 swapout
Post by: TurboCoupe50 on January 02, 2008, 01:12:44 AM
No real notes, did it back in '99... The '87-'88 TCs are unique and not like any other Bird/Coug, many of my changes would not apply to your swap... My 5.0 harness came from a '87 Tbird(had a parts car), converted it to mass air prior to installing it...

Mostly it's matching colors, Stang and Bird  color codes are generally the same... A few are sometimes different, as occasionally similar colors are substituted when the harness is manufactured... Mainly your going to find each year the harness' are revised and probably different from prev years... Have no experience with any year 3.8(that isn't General Motors)...
Title: I have done it!
Post by: billwrks on January 18, 2008, 07:42:02 PM
If you have any Qustions just ask! I had an 84 cougar with 3.8 swaped with the 302 and now 351w
Title: 3.8 - 5.0 swapout
Post by: Thunderhawk on January 18, 2008, 08:18:38 PM
What year 302? Mustang donor? How about wiring issues?
Title: 3.8 - 5.0 swapout
Post by: Haystack on January 18, 2008, 08:33:18 PM
You could always just swap k member instead of getting "ultra rare" brackets...

Get a 86-88 5.0 harness from a tbird or cougar and your set...
Title: 3.8 - 5.0 swapout
Post by: CougarSE on January 19, 2008, 12:02:49 AM
NO, get an 86 5.0 harness and it will PLUG in.  No offense to you but I've said this probably 20 times on this board so some of the others could have told you that already.

87 and 88 are a little bit easier to interchange the harnesses between them selfs but are still not plug and play like sticking with a same year harness is.  86 is an odd ball.  The connectors are the older non weather sealed style (save for a few of them).  87 and 88 shared alot of the connectors but 86 is different in many ways..  The location of the dash interface is different, the fuel pump connector is different and so forth.  Its not worth trying to modify. 

I swear I need to write this all down again.. and have it stickied.. Stick with the same year harness and it will plug in!!