GT40P HO Projects

[FarmerBen]

Ok kids. I am officially an ebay addict. I have my 1993 Thunderbird motor and trans (I know the trans is too short, but it should be a good core). I even have the GT40P heads. They are in the mail. If anyone has any tips from similar transplants, I'd like to hear from you. I am stil shopping for a new roller cam. Comp Cams has one that looks good. With a little advance I think it will be prefect. Lower stall and low end torque is the goal.

I am hoping the wiring harness is reuseable from the Thunderchicken. I need an ECM yet and some headers. I want to get the heads rebuild before I get the pisons picked out. I want to get a set of roller rockers too. Kind of getting one thing at a time to make sure it all fits.

I need to measure the accesory mounts from the bird as well. I want to use them and relocate the A/C like it is on the birds. Then I won't have a clearance issue for the mass air. That is if it fits. Then I can use more Mustang stuff like the underdrive pullies, etc.

Has anyone else on here swaped out the AOD guts to the newer style tans? I like the idea of having the lower 1 and 2 gear so you don't have to have such a low rear end. I also like the better OD band. I am thinking 3.27:1 is the ratio back there for good launches, but respectable fuel economy. I want to get low to mid twenties for fuel economy.

She's coming together, I just want to save myself some grief if I can learn from your experience.

[85crownHPP]

all the 5.0 engine stuff should work fine with the new parts as long as the ECM matches the parts you use.
A few guys here have AOD cases with the newer transmission gearsets in them if thats what you mean. Its supposed to be a pretty common thing, but I hear the parts arent availiable new anymore.

[CheeseSteakJim]

I think Baumann still makes them but don't quote me on that. Might be something to look into.

[mrltd]

You might want to read up on the HO swap threads (FAQs). And some of the members cars threads.

Trans short? You have a towncar? If not, the trans is the same length.
Wiring harness? Not even close. And not needed at all.

From what you have described- AC relocation, and mass air.... look at blaze86's vic. You will need to change everything under the hood and have some custom hoses made up. Or look at mine and the setup in it.

[gadget73]

93 Tbird trans will swap right into a Ford or Merc. Lincolns are the only ones with special transmissions. Swapping the tail parts properly requires complete dissassembly of the trans. the cheater way is to just swap the housing, but the output shaft engagement won't be complete. It works, but its not ideal. Shift lever will also need to change but thats no big deal.

If you want the trans gear ratio change, you'll need a 4R70w donor trans to rob the planetary set out of. It does fit into an AOD, but the specifics I do not know.

Tbird wiring harness and ECM is not useful. If you're working with a SEFI car, the stock wiring harness stays. If its not a SEFI car, you'd want a harness out of one since it'll fit right in. ECM for a Tbird has a very different pinout, so it won't work right on the stock wiring harness. The usual suspects for an HO swap are either Mark VII if you're staying speed-density or the Mustang A9P/A9L brain. You can do mass air with the intake facing the same way as stock. It requires some mods to the wiring harness, but its pretty minor. I've got all the parts in the trunk of my car to do this, but so far I've been too lazy or busy to make it happen.


What are you working on anyway?

[FarmerBen]

Really...

I am working toward putting this combo in an 86 Crown Vic that I don't have yet. I'm still in search of mine. I sold her two years ago and want to try to buy her back. Should have never sold her. Dumb things you do to try to please women. Big mistake, the car was more reliable. ;-)

I thought the Crown Vic AOD was longer too. Interesting. I am not a trans guy, so I am still trying to get up to speed on them. The AOD was no good as the OD band was going to heck, and I like the idea of the 4R70 gears . So I am just getting the motor ready. She had 166,000 on her when I sold her. The body was perfect when I sold her. If I come up empty on getting the old car back, I want a coupe. either way it is going in either an 86 or 87 Crown Vic.

I've been reading up on the other threads. They have been helpful. The motor is something I always wanted to build up. I am not sold on the Tbird intake. I may buy another one if I see the right deal. I've got a shop manual coming for the 93 bird so I can study up. I want the mass air set up so it will not freak out the ECM. This 93 motor/trans came up so I bought it. $250 scored me a set of GT40P heads. They should be here this week.

I like the idea of the newer computer and harness. Everything is already there with the motor. The harnesses are the same? The bird has an oil pan sensor and some other things I didn't recognize from my old Crown Vic. I'd appreciate any insights into the wiring. I was just going to do a full on swap to the newer ECM and wiring. There has to be some wiring to the trans. The lock-up converter needs a signal. I decided to stay with the AOD to have the mechanical speedo. I'd rather just have the 4R70, but I don't want to mess with the cruise and speedometer. I figured if I stayed with the AOD 93 was best since it was the last year. That mandated the ECM be of the same vintage. I like the coil packs on the newer ones, but the 93 ECM didn't use that. The last of the 5.0 Exploders look like a better engine/trans set up, but it looked like a conversion nightmare.

[FarmerBen]

Harnesses

So I am curious about the wiring harnesses. I have been doing some looking. What harness works for the 86/87 vics? I don't want to have a big mess to untangle. Will a Mustang harness work? Or does it have to be a Crown Vic? I want mass air, but do I just need the conversion if I have a 86/87 harness and ECM? Teach me o wise ones, I am looking for knowlege.

[gadget73]

Just use the stock wiring harness and add the mass air if you want to do it. None of the Vics that you're likely to ever find came with mass air from the factory. The mass air conversion stuff for 86-88 Mustangs works on these. The "kit" is a 4 wire plug and a short list of simple wiring changes at the ECM connector. Basically you move 2 pins and splice something in. The Mustang harness has all the parts on the wrong side of the car, so it would be a pain to get it to sit in there properly. You could make it work if you didn't mind un-taping the harness to re-route the wires but modding the stock harness is a lot less work.



(all this from the guy who's had the stuff to do the mass air swap in the trunk of his car for a year now)

** yes, there was a mass air 5.0 Vic. 1991 California models had it, but they're exceedingly rare and finding one of those wiring harnesses would be highly unlikely.