Hi

I'm studying a way to drive my 1983 T/A into the 21th Century replacing the old and broken TH-700 R4. (I work with 5-to-8 speed automatic sedans)

Looked for a 6-speed GM auto, but it's really PRICEY ! Didn't find anything cheaper than 4 grands

Engine is soon gonna be a LS-1 GM crate engine, do anyone has a solution to avoid the good but 4-speed only 4L60E ?

 

Theres a thread going on in the LSX sub forum that deals with putting a trans behind a LSX engine. It deals with mainly older style transmissions, but should give you an idea of options if you are open to the idea of a manual swap. Cheapest thing to do would be to rebuild the 700R4, get a crank adapter and flexplate, and bolt it to the LS1.

Otherwise, its a manual swap, or you have to use a trans that will bolt to an LS engine without an adapter.

https://www.thirdgen.org/forums/ltx-...rly-style.html

 

Well, lets looks at what a 6l80e has to offer vs a 4l60e, 1. Strength, out the box the 6l80e is stronger but for the cost you could have a stronger 4l60e built. 2. Lower first gear (numerically higher) allows you to run a higher final gear (numerically lower) and still get good torque multiplication and highway speed. 3. Marginally better overdrive .667:1 vs the 4l60e .7:1....the overdrives are so close they wont really make a difference.....The 6speeds are needed because cars are getting alot heaver now days, so to get their big selfs moving you need as much torque multiplication as possible and once your moving you want to get as best gas milage as possible so in this role a 6 speed is needed with its massive first gear and over drive allowing you to run a smaller rear gear so you can have your cake and eat it too.... For your car especially with an aluminum LS1 swap the 4l60e will do fine, it will be plenty "modern" and is really one of the best autos for the job.....and dont doubt their strength if built right they can handle plenty of abuse. My friend runs a built 700r4 in his 9 second 396LT1 nitrous transam and abuses the crap out of it and no problems in the couple years hes ran it....

 

Thanks guys.
I consider automatics only, at least fot this car. Iam also sure a 4L60E will make a good job, especially on a alloy-engine BMR-equipped car. It's the way I plan to go currently, BTW.

But Man... gas is $6.50 a gallon here in France, and can reach $8 anytime. And once you drive an 8-speed auto car, you are so much in love that you want the closest possible for you F-baby.

Burning Porsches, Audi S8s and japanese bikes has no price. Well, yes, its has one : $4000 for just a trans. Too much for me. I just wish I can do it for less...