Ta >>> Tta



Just wondering if it is hard to convert a TA to a TTA i might buy a 89 Trans Am GTA and thought that if i saved some more money might be kinda fun to convert it over to the 3.8 litre to make it a sleeper.

Thanx Aaron

Look at GM High Tech performance magazine, there was a guy in there two months ago doing conversions into almost anything (4th gen, el camino, 3rd gens, etc.). There was also some posts under general tech a while back.

Ken TTA#1426
Well as I understand it this is what you need:

A TA to use as a base.

A set of front wheel drive 3.8l heads from an 87-89 GM car. I have looked into this a little and have never come up with a casting number, or even a thought that one number is better than the next. One gut on the tta board on topica recently pulled a salvage yard set to port. He even pulled the front most head from two different cars for the sake of ease.

A doner 86 or 87 TR so that you can get everyting else you need like the block, harness, ecm, tranny, etc.

Pistons - TTA pistons are differnt than TR pistons. You can get an aftermarket set of TTA pistons is you like but I assuem you can keep the flat tops from the TR. There will be a CR difference.

Motor mounts. Not available. One of the vendors is working on a poly set. They should be available soon. You could just make them.

Transmission cross member. Unique to the tta. Would have to make one up.

Odds and ends:

The tta headers are different. Don't know if the TR ones fit. ATR may have TTA headers, never looked. There is a guy on the the tta list now selling a pair.

AC hard lines are unique. I think johnsperformance.com has them.

Oil cooler is different. How does a TR do it? The tta cycles coolant through a manifold between the block and filter. Johnsperformance.com has the manifold, not sure about the plumbing. Just use and aftemarker oil cooler. Cheeper and easier.

Intercooler is different. I think the physical size is the same as a TR but the fins per/in for a tta is 12 not 10. Use the TR intercooler or upgrade.

You will have to fabricate an intercooler scoop, but I have heard a TR can be made to work. The tta one has reliefs for the radiator fan motors, I don't think the TR does. May not be an issue in a conversion.

I am sure a drive shaft will have to be shortened or made up. If I was going through the trouble I would have an aluminum one made.

You have the entire process worked out. Thanx for the info it really helps. Im not sure if im going to go with entire setup of a TTA I just want to put a GN drivetrain because the 305 ci doesnt cut it. Im going to print all this info out and come back to it when ive got the money to do it.

Thanx Aaron
Your welcome. I hate to say it because I love my TTA, but I would do something different if I were going through the trouble. I have always liked drag cars over corner cuters so I would be more inclined to pull the 305, gut the car as much as you can stand and get away with for emissions, tie the frames up to stiffen the car, then drop in a real V-8 to end up with more of a drag car. Eventually the rear end and rear suspension would have to be worked out as well. No computer to deal with, a lot less cost for the same speed, less fabrication, better parts availibility.

As for real V8, it would be a Pontiac 400 or 455.

I know, I'm odd, but it could be those two late 80's third gens I was eyeing last night while driving home and mulling over my '68 firebird project.

good luck in what ever you do, just make it your own!

Originally posted by tta583

Motor mounts. Not available. One of the vendors is working on a poly set. They should be available soon. You could just make them.

The motor mounts ARE available. Federal Mogul makes them and they are $25 a piece Canadian.
Great, do they have both the driver side and passanger side ? Part No and or web site to order ??

Best Regards


TTA #1078

Great news!
And that is in Canada right?

Hey Jan!

Welcome! Do we have any places left to sign up to? ;-)
oh boy :D motor mounts bolt to MOTOR PLATES....the plates are on the MOTOR..special pieces...GM got good money when they were available....Ill post some pics of them ...got a few sets :)
i have the plates, pistons(16kmiles) and the headers!!!!r

make an offer and i will sell them! :eek: