Update 02/19/2012: I've decided I'm going to pick this transmission up, Here are my thoughts going forward. I'm going to tear it open and take a look around make sure everything looks fine. He said it has a "Rebuilt by GM" sticker on it so I'm tempted to simply put a Transgo Shift Kit in it, and nothing more. I'm pretty sure the stock 4L80e should handle 800hp running through it in a "lighter than truck" car/wheels/tires like my GTO.

I plan to keep the stock torque converter. If I recall, it has a 2500 stall to begin with. For turbo, I'd prefer higher, but I will manage.

Next step is to order the PCMs For Less TCM Harness, and start cutting my notch on my frame so it can hook up to the trans. Hopefully this will allow my PCM to shift the 4L80e flawlessly. After that it's a matter of digging in my HPTuners to get the shifts points where I want them.

Finally, and I still haven't decided, I need to either customize my stock driveshaft, or order a new one. GForce has a really nice carbon fiber one that is ready to bolt right onto the 4l80e, and I'm pretty sure Driveshaft Shop can also make me one for less, but I think I have to supply them the proper yoke. If I get someone to customize my driveshaft or make a new one it will probably run a couple hundred bucks, and probably doesn't have the same R&D put into it as GForce. I think I may take the bullet and spend $1400 on the CF shaft from them. I'm sure I'll be happy in the long run with it anyways, and should result in less headaches overall.

Any advice on whether I should beef up the 4L80e anymore? Any other additions I should make aside from the shift kit?

Thanks for any input!





02/16/2012: Found a pretty good deal on a 1992 4L80e out of a Chevy C3500. I'm going to be swapping a LR4 into my GTO and I want to link a 4L80e up to it. The reasoning is because I need something that will handle the TT power. The 4L65e just won't cut it.

My question is...

Should I have an issue hooking a 1992 4L80e it up to the LR4 block itself?

The driveshaft will be custom. A couple of GTO shops are making them for the 4L80e swap, so that should be covered.

I have a few options on how to get the ecu to shift the trans, so that shouldn't be an issue as well.

I'm just worried about the trans hooking to the engine properly. To hook the 4L80e to a LS2 we need a custom torque converter, etc. I'm just kind of hoping it's a direct fit.

I'm pretty sure my 2005 LS2 is a 24x reluctor, so the ecu should read for a 24x. If I recall, the LR4 and the early 4L80es are 24x also. Can anyone confirm this to me for sure?

Thanks for any tips. You guys have been a great help so far with everything!

 

Forgive me....

Your putting a frukking 4.8 in a GTO??

 

Yes sir! I'm excited as well for many reasons! Check out my intro thread I made yesterday. It will give some details.

https://www.performancetrucks.net/fo...05-gto-497183/

 

Yes? Did you miss his other post?

Sounds like a bad *** ride to me. On topic though, I have no idea.

 

Dude, seriously this is like calling your mom and telling her that your brother got shot, hang up, then call back an hour later and tell her it was a squirt gun.

4.8TT should have been in the first post lol

 

03 and up Chevy Express 2500 and up vans came with a 4.8 and 4L80E , Id use that option rather than the 92 transmission

Also 05 LS2 in the GTO is a 24 tooth reluctor.

 

Haha! Awesome. It was subtle, but it was there.

"Found a pretty good deal on a 1992 4L80e out of a Chevy C3500. I'm going to be swapping a LR4 into my GTO and I want to link a 4L80e up to it. The reasoning is because I need something that will handle the TT power. The 4L65e just won't cut it."

 

Would definitely make things easier, but if the 1992 will work, it may be worth it as I will only be paying $100 for it. It seems like an unbeatable price, especially for one in working condition.

 

Found a pretty good deal on a 1992 4L80e out of a Chevy C3500. I'm going to be swapping a LR4 into my GTO

This is where I stopped reading

 

If this works out for you pass along to the GTO forums that I have two 4.8's in Denton, Texas that nobody on PT wants...