Out with the old...in with the older, 89 GT foxbody build
03-09-2013, 11:18 AM
#1
Out with the old...in with the older, 89 GT foxbody build Hi guys, just putting this up here to ask questions and to share my build. I currently have a 99 TA that I have spent many moons on and I have come to the point where I need a change. Unfortunately I can't buy just buy a new car so I'm going to try my hand on doing a swap. My plan is to part out my TA, keep the LS1 and 6 speed, and use the money from parts sold to buy a foxbody Mustang. I like the foxbodies better than the SN95, and I can't afford a 99 or newer Mustang. Part of my plan has already come into fruition. I was able to sell my intake and brake kit to buy a 1989 Mustang GT. I got it for a good price, but unfortunately whoever painted it didn't know anything about prepwork. On the plus side, as far as I can see the car has no rust on the undercarriage or in the engine bay. There is a little surface rust inside where the the spare tire goes but it doesn't look too bad.
My plan is to strip my Trans Am, sell the parts off of it, and using that money, buy parts for the Mustang. On the Mustang, I'm going to strip the inside out, make sure there is no major rust, and also strip the engine bay out. From there I'm going to paint the underside, the interior, and the engine bay. I'm going to leave the exterior alone until I have the engine in and running and the car is able to roll under it's own power.
I have some questions for you guys who are doing or have done this swap. First the biggest issue I have is wiring. I'm planning on pulling the pcm and engine harness from the TA and having it rewired by a company like BP auto. The thing is, I have read that the the mustang harness is separated into a body and a engine harness. Where is that separation point in the mustang, like the physical location? And also where is everyone putting there LS pcm in the mustang? I also plan on swapping my gauge cluster over, is there anything wiring wise that I need to worry about doing that?
Power steering: it doesn't like too complicated but is everyone using the stock mustang powersteering rack, an LS based powersteering pump, and the the fittings to go inbetween that? I would like to go to Flaming River manual power rack and pinon but I don't think my budget will allow me to do that.
A/C: How is everyone doing the A/C system. I would like to be able to run A/C on my car. The Mustang is primarily going to be a street car and A/C is nice in the summer. The stock A/C system is still on the Mustang, and I have my f-body A/C system. I've done some research on this and haven't found a real answer.
Everything else seems to be pretty much straight-forward, just buying the parts and bolting together. I plan on doing AJE front suspension with dynatech headers.
Thanks,
Rusty
My plan is to strip my Trans Am, sell the parts off of it, and using that money, buy parts for the Mustang. On the Mustang, I'm going to strip the inside out, make sure there is no major rust, and also strip the engine bay out. From there I'm going to paint the underside, the interior, and the engine bay. I'm going to leave the exterior alone until I have the engine in and running and the car is able to roll under it's own power.
I have some questions for you guys who are doing or have done this swap. First the biggest issue I have is wiring. I'm planning on pulling the pcm and engine harness from the TA and having it rewired by a company like BP auto. The thing is, I have read that the the mustang harness is separated into a body and a engine harness. Where is that separation point in the mustang, like the physical location? And also where is everyone putting there LS pcm in the mustang? I also plan on swapping my gauge cluster over, is there anything wiring wise that I need to worry about doing that?
Power steering: it doesn't like too complicated but is everyone using the stock mustang powersteering rack, an LS based powersteering pump, and the the fittings to go inbetween that? I would like to go to Flaming River manual power rack and pinon but I don't think my budget will allow me to do that.
A/C: How is everyone doing the A/C system. I would like to be able to run A/C on my car. The Mustang is primarily going to be a street car and A/C is nice in the summer. The stock A/C system is still on the Mustang, and I have my f-body A/C system. I've done some research on this and haven't found a real answer.
Everything else seems to be pretty much straight-forward, just buying the parts and bolting together. I plan on doing AJE front suspension with dynatech headers.
Thanks,
Rusty
03-09-2013, 08:50 PM
#2
12 Second Club
iTrader: (2)
Join Date: Apr 2009
Location: PNW
Posts: 900
Likes: 0
Received 0 Likes
on
0 Posts
Im doing the same as you.use as much as you can off the ta.i had bill at bp build me a custom pnp harness thats awesome.I have not figured where im gonna mount my pcm yet tho.for the p/s im gonna use fbody pump and ford rack the connect the high pressure line with a tube union.do a search on the ac,theres a recent thread going over it or you can look thru my previous posts and find the thread.
03-10-2013, 11:34 AM
#4
Most are putting the engine computer under the dash as stated above (kick panel works best). If you are using an F-Body gage cluster we have a harness that will integrate it or if you just want the f-body gage cluster we have that wiring as well separate. The instructions are available on our website for free download. Our plug and play harness for that is $499 if your looking to buy new.
Jon
PSI
Jon
PSI
__________________
Your Source for LSX Conversion Parts!
www.psiconversion.com
Ebay Store
Facebook/psiconversion
Instagram/psiconversion
'Dont Let EFI Pass You By!'
Your Source for LSX Conversion Parts!
www.psiconversion.com
Ebay Store
Facebook/psiconversion
Instagram/psiconversion
'Dont Let EFI Pass You By!'
03-10-2013, 03:23 PM
#5
12 Second Club
iTrader: (2)
Join Date: Apr 2009
Location: PNW
Posts: 900
Likes: 0
Received 0 Likes
on
0 Posts
Only issue with the cluster is the fuel gauge.still have not found the correct way to make it work.my question is how do you get the connectors to the stock ford location with a stock fbody harness?
03-10-2013, 05:27 PM
#6
Stang have you played with the settings in HP Tuners for the fuel gage?
Jon
PSI
Jon
PSI
__________________
Your Source for LSX Conversion Parts!
www.psiconversion.com
Ebay Store
Facebook/psiconversion
Instagram/psiconversion
'Dont Let EFI Pass You By!'
Your Source for LSX Conversion Parts!
www.psiconversion.com
Ebay Store
Facebook/psiconversion
Instagram/psiconversion
'Dont Let EFI Pass You By!'
03-11-2013, 12:21 AM
#7
Pics or it didn't happen. 
Why swap gauges? I never understood this but I've never owned a Mustang, I only watch them from the mirrors.
Seriously, do their gauges really suck or something?
The power steering can be run from the LSx pump with custom hoses and a pressure reducer. This isn't super expensive and much cheaper than a manual rack. The only benefit I see to a manual rack is weight which must not be a huge issue if you are keeping AC.
AC can be custom hoses to the F-Body compressor as well or you could use the Ford compressor and integrate it into your accessory drive like I did. This option requires fabrication skills and tools. I did it so I didn't have to discharge my AC lines. Since I don't know your skill level or what tools you have access to I listed both options.
Why swap gauges? I never understood this but I've never owned a Mustang, I only watch them from the mirrors.
Seriously, do their gauges really suck or something? The power steering can be run from the LSx pump with custom hoses and a pressure reducer. This isn't super expensive and much cheaper than a manual rack. The only benefit I see to a manual rack is weight which must not be a huge issue if you are keeping AC.
AC can be custom hoses to the F-Body compressor as well or you could use the Ford compressor and integrate it into your accessory drive like I did. This option requires fabrication skills and tools. I did it so I didn't have to discharge my AC lines. Since I don't know your skill level or what tools you have access to I listed both options.
Trending Topics
03-11-2013, 12:33 AM
#8
12 Second Club
iTrader: (2)
Join Date: Apr 2009
Location: PNW
Posts: 900
Likes: 0
Received 0 Likes
on
0 Posts
No I have not yet.i think the main issue in my case is that the gm sender uses a 5v ref for the pcm to calculate and a signal wire where as the ford unit reads strait ohms.how ever I think you could undo the ground on the ford sender and turn it into the 5 v ref.but I think ive come to the conclusion id rather adapt the speedo to work.only issue with the ford gauges is the tach is very inaccurate.I have an idea of using a android tablet with the torque app and a elm327, but it probly wouldnt fit great.
03-11-2013, 10:26 PM
#9
To get the speedometer working, I used a Dakota Digital SGI-5 converter box. I can't remember the tech bits, but the Ford speedometer requires a different input than the GM PCM allows and this will convert the signal accordingly (or adjust for gear changes which can be done in the tune).
03-12-2013, 06:10 AM
#10
Pics or it didn't happen.
Why swap gauges? I never understood this but I've never owned a Mustang, I only watch them from the mirrors. Seriously, do their gauges really suck or something?
The power steering can be run from the LSx pump with custom hoses and a pressure reducer. This isn't super expensive and much cheaper than a manual rack. The only benefit I see to a manual rack is weight which must not be a huge issue if you are keeping AC.
AC can be custom hoses to the F-Body compressor as well or you could use the Ford compressor and integrate it into your accessory drive like I did. This option requires fabrication skills and tools. I did it so I didn't have to discharge my AC lines. Since I don't know your skill level or what tools you have access to I listed both options.
Why swap gauges? I never understood this but I've never owned a Mustang, I only watch them from the mirrors.
Seriously, do their gauges really suck or something? The power steering can be run from the LSx pump with custom hoses and a pressure reducer. This isn't super expensive and much cheaper than a manual rack. The only benefit I see to a manual rack is weight which must not be a huge issue if you are keeping AC.
AC can be custom hoses to the F-Body compressor as well or you could use the Ford compressor and integrate it into your accessory drive like I did. This option requires fabrication skills and tools. I did it so I didn't have to discharge my AC lines. Since I don't know your skill level or what tools you have access to I listed both options.
