02SSTtop

Awhile back I posted I was willing to swap my T56 over to an 4L60E so that the wife could drive the car.
I found a local guy who has a freshly rebuild auto willing to make the swap. Is there anything I need in the way of PCM tunning after the swap is done?
I have found lots of info using the search but it all was about swaping an auto for T56 and not much I could find on doing the reverse.
Thanks in advance for any help anyone can offer.

bbond105

You will need your PCM tuned or a PCM from a auto car.

mrvedit

You will also need to get an add-on harness for the 4L60E. IIRC Speartech and perhaps other vendors sell them for around $200. It should include directions on how to pin it into your PCM connectors; you then run it back to the trans.

Its a big project to swap from a T56 to an auto, and even a bigger one to go the other way. I half way seriously suggest swapping cars with someone who has a 4L60E and now wants a T56.

02SSTtop

That was a thought but I because of the climate where I live its hard to find one that doesn't have rotted out floor boards from being drivin in the winter. I think if the wife really wants her own T-Top car for the summer months I will pick her up a nice V6 camaro or firebird or a decent LT1/LS1 at the right price. She doesn't do the track or anything so she doesn't need anything more then that. I alrady have to much in vested in mine to start swaping the T56. Plus it will kill the value on the car down the road it came from slp with the 6 speed. And lets face it they kick *** and are fun as hell to drive. I have to drop the trans this spring because either the rear main or the cover is leaking is it worth it to upgrade to an ls7 clutch?

mrvedit

Understand that you don't want to swap cars.
I don't know if the trans swap would affect value; depends upon the buyers.
I didn't really want to completely discourage you, just have you realistically understand the complexities and costs.
I certainly would not swap; even my wife likes to drive a manual.

bbond105

I did the swap it’s not that bad. I had a donor car so I had the wiring harness, PCM, shifter, pedal assm and all of the small pieces that you don’t think of until you need them. I also cut the trans tunnel out of the donor and welded it in over top of the shifter hold left by the t56. By doing this the shifter bolted up as if stock. You will also need to hook up the neutral/back-up light switch for the PCM to control idle. If you have to buy all of the parts it can be a big undertaking. If you decide to go ahead with the swap I have wiring diagrams for the neutral/back-up light switch and pedals so all the safety features, cruise control and torque converter tcc will work. This project is not for the faint of heart but is doable.

mrvedit

First Mr Bond says "it's not that bad" and then says he had an entire donor car. Yikes, that makes it sound rather scary.
Anyway, another thread just started about swapping from a T56 to a 4L80E. While the trans is different, much of it would apply to you too and a swap to a 4L60E is a bit easier:
https://ls1tech.com/forums/automatic...80e-build.html

Good luck, either way you go.

bbond105

The donor car was my Camaro that was totaled, so I didn’t just go out and buy one, it was the reason for the swap. The Camaro had my modded engine, trans and two week old Yank torque converter that I swapped into my current car that had a t56 when I bought it. A donor car is not necessary but it sure made it a lot easier. Note going from a t56 to 4L60E you will not have to change the length of your drive shaft.