Im currently heading toward dropping a 5.7LS1 into my 1991 firebird and I'm wondering what transmission I should pair it with.

I want a good automatic (dont want to crack firewall for a manual) that will be able to keep up with the mods ill be doing on the engine.

So if i cant rebuild my 700R4 (i believe thats what I got, dont know if itll do the trick) I need to know a good tranny for this LS1.

 

If you are looking for a strong 700R4?, give me a call at 800 7763288 M-S 10-6 PST and I will answer any questiions you might have on the 700R4, and which torque converter to use. If you get a chance go to my website at www.pro-built.net and look at the Street/Strip transmission and you will see exactly what I do them. They come with a one year warranty. If you interested, let me know?

 

yeah Pro Built Automatics is the guy to get your trannies and parts from, when its time for a rebuild on mine i am definitely getting the stuff i need from him, i hear alot of good things on thirdgen about him and the company..

 

Welllllll I dont know if I want the 700R4... im looking for some input here.
will my 700R4 handle the LS1? Will it even match? Im clueless as far as trans go =P

 

Will a 700R-4 handle an LS1? Absolutely. How do I know? Because the LS1 got mated to a 4L60-E which is an electronic version of the 700R-4. Many revisions have been made over the years to the 4L60-E, but the internals are still basicly the same.

Problem is, the LS1 uses a computer controlled transmission (4L60-E), and expects to see inputs and outputs from the transmission, so if you use a 700R-4, you will have a constant codes stored in the PCM.


P.S. I just thought about it, I don't know if the bellhousings are the same... Never had a chance to compare them.

 

oh man this sounds complicated...
i want a no frills solution - like i want a tranny thatll just pop on and work with the LS1 - so if the 700R4 I have isnt electronic i should just get the 4L60E right? Thatll handle what I have in mind correct?

 

Someone correct me if I am wrong, but complication is the order of the day here. By changing to an LS1 you will need a PCM as opposed to the simpler ECU. This will entail a complete wiring harness change as they are two completely different animals. As far as the "E" version of the 60 series box I am pretty sure they are a direct bolt in. I don't have the part # handy but GMSPO offers a connector kit to install an "E" into earlier version vehicles that don't have a PCM. I think the "E" uses a five pin TCC connector as opposed to the four pin the straight 60 uses. You might check out the GM performance catalog. If you require more info on the hydramatic transmissions go to www.gmpowertrain.com. You can get HP and torque specs. You might want to look at the 4L65E, 380ft/lbs torque.

 

If you want a tranny that will "pop on" and work with the LS1, then the 4L60E is definitely the one you want.

 

Torque level on the 4L60E?
The transmission generates ALL the torque?
i need to learn more about transmissions

 

Torque in it's simplistic term is the amount of force measured in this case in ft/lbs. Torque is a major factor when building or selecting a transmission. It determines the strength of the parts needed when designing just about anything mechanical. Same principle when you change a head, you torque the bolts to a specified rating usually in ft/lbs. Smaller fasteners usually are in in/lbs. Torque is applied to the trans from the engine and hopefully to the tar. I know all these young guy's here like the 4 speed boxes, but I still like the old Turbo 400 for high performance applications. Just can't teach an old fart new tricks or something like that. Guess it's because I have one sitting next door in my friends garage ready to go if need be.

 

You need a 4L60E, but not just any 4L60E, you need one that was behind an LS1. The bellhousing pattern is different so earlier 4L60E's (LT1) and 700R4's won't bolt up.