View Full Version : SC 3.8 to 5.0 swap. please help. kinda long

05-20-2003, 03:07 AM
as like everyone on this board i love my 3.8. but i think the 3.8 will not be as economical in the wallet department to make it produce hte power iwant as a 5.0 would. i read all the seach ones and get different answers. im tryin to geta solid yes or no on things. i understand the mustang headers won't clear. so that part is fine. ill work that out later. the part i need a for sure answer on is the tranny (until i throw a t-5 or a t-56 tremec in there), the wiring i will get a 5.0 t-bird harness complete with ecu for it, i believe i read the motor mounts will bolt up fine from what i've read, exhaust ill take care of when i go savage and someone fit dual 3" under there as far back as i can then cut it off with borlas (already ahve them), i guess im jsut want to get a solid yes or no on it. i have a 90' SC 5-speed. i know i need a 90+ year of a 5.0 for smog in cali. i just need to here if there is something BIG im leaving out except fora bit of down time. thanks for teh help. im not a member of TCCOA.com because it costs money and i don't have it right now to spend on membership. or i would post htere. i check their search function also. if you guys see any problems taht i missed please clue me in. i also understand the hood clearnace problem. thanks again and agani and again for answering all my dumby newby ?'s!!! this board is awesome. steve.

05-20-2003, 01:06 PM
Uh...im pretty certian that the bellhousing bolt patern is identical on the 5.0 and the 3.8 (they used about the same AOD on the 89-91 5.0/3.8) so it should bolt right up. And i know for certian the stock 5 spd will handle the torque output from a 5.0 (assuming its not some overmodified horse of an engine :D ). There are 2 potential difficulty areas i can see.

1) Finding a suitable clutch setup (might be the same as the 3.8 but im not certian, maybe u could get one from a rustang.)
2) The ECM from a auto bird might get upset and throw codes when it dosent have the AOD strapped on there (because its a 5.0 it probably didnt have a AOD-E so it may or may not be an issue)

I wish i could find the article detailng how to swap an auto to a manual from a cobra...its out there somewhere. I could see it being of some use. If i find it ill post it here.


05-20-2003, 01:41 PM
The easiest thing was that I had an entire parts car to get my engine/electronics from. I don't think they made a 5.0 Tbird till 1991 and stopped after 1993.

I can't write it out in total detail, but as far as the motor swap goes, it is pretty straight-forward. If you have ALL of the engine hardware (motor mount brackets, accessories, headers, etc.), there really isn't much problem. The wiring is the fun part, so be prepared to have the wiring diagrams from the year of the car you are getting the engine from and the year of your car. This will help much. Get the vacuum diagrams for each as well.

About the bell housing, they are identical. Bolting up the M5R2 5 speed to the 5.0 is no problem, however you will need the Clutch, Pressure Plate, and flywheel from a 91 model Ford F150 with 5.0L engine and 5 speed trans. The F150 used a Mazda M5R2 transmission as well, but the trans itself varied from ours slightly. Depending on how much power you are planning on making with the 5.0, the 5 speed should hand the HP and Torque pretty well. If the SC engine makes 300 ft/lbs of torque, I am sure that the M5R2 trans can handle the 5.0's torque as well. Just don't try to kill the tranny by speed (almost clutchless) shifting, that will kill any transmission over time.

If you are converting from an AOD auto to a 5 speed, you will need to get ALL of the clutch components from a SC 5 speed. This is quite a project to undertake. Personally, I considered it, but the amount of work involved really disuaded me. I went with a built AOD and called it a day. I would however recommend that if going with an AOD to use one from an SC and build it up,also use a steeper (numerically higher) rear gear ratio (3.55 or 3.73). The factory AOD's like to BOOOOOOGGGGG!!!

If you have any questions, fell free to IM me or email me with them, I will be glad to help you out any way I can.


xr7 Ben
06-26-2003, 11:07 AM
I have done a 5.0 HO swap to a 89 tbird sc, it was about 2 years ago so I might be forgetting alot, But two big concerns were hood clearance, and the steering column. the 5.0 intake has to be a short style 94 and up I think, by chance the 5.0 we bought was out of a 95( i think) mustang so we were alright. The engine mounts we used I fabricated, which might have caused the problem of the steering column hitting the factory 5.0 headers. The project took me along time and a lot of beer. Most of my problems were spent combining the 5.0 engine wiring harness into the SC wiring system, I spliced every wire. Feel free to email me with any questions and I'll try to answer them to the best of my knowledge.

XR7 Dave
06-26-2003, 08:47 PM
For those who did this with an 89-90 model SC, what I want to know is how you integrated the cruise control since that is controlled by the computer on the 89. Thanks.

91 XR7
06-26-2003, 10:56 PM
I have a `write up' on a '89/90 S/C to 5.0L swap, and the only thing is i do not have any info, yet, on the cruise control.. the info is being gathered slowly, and should be done ahh whenever :)

But it wouldn't be hard to wire in the seperate Cruise control module, since the buttons are the same, and the external `specs' (from the servo, ect) are the same.. it's the Crossing over of the wires from one to the other...

ALso the flywheel can be used from any 5.0L F150 from '88+?? and you have to use a '93-96 < small Diameter F150 5.0L/5spd > Starter... clutch is any S/C or F150 clutch

Also i think the M5R2 would have a better life behind the 5.0L since all the power is up higher then the S/C where like what, a S/C has nearly 300ft/lbs at @2000-2500?? verses the 5.0Ls 300ftlbs max at 3000?? < stock for stock >

Also doing a 5spd swap isn't hard, and can be completed in like 36 hours of work at the most.. think it took my like 2 hours to drill and hang the Clutch pedal/master and swap the brake arm to a 5spds... the tranny swap took like 3 days of working MAYBE 6-7 hours a day taking my time and with like 12" of clearence :)

06-27-2003, 01:03 AM
sell the SC and get a 91 LX with a 5.0 easier cheaper and you dont have to kill a SC