Going 4l80E, I'm off the deep end again!

So I've been needing to get a transmission for a while and came really close to pulling the trigger on a billet CK unit. However, I still wasn't happy about the idea of having another 2oo trans. A good buddy of mine has a 4l80E behind his supercharged 502 truck and it works amazing. I really like the trans controller and the options it gives him (sift points, lock up speed, Shift firmness, etc....). Plus I plan on road racing the car and figured the manual mode with some paddle shifters may be the ticket. Either way, yesterday I picked up 2 used 4l80E transmissions, one from a 97 truck and the other from a 2000 (kind of a 2 for 1 deal, too good to pass up). I'm planning on installing one of these to see if I can get it to fit, if it does, I'll probably get Jake's performance stage2 kit and rebuild it. Now I've been searching on this forum a lot and it seems that most people who have these transmissions have also done a LS motor swap. I couldn't find anyone who has put the 4l80E behind the turbo 6. If you have, please help me out with the following questions.

1. Does the summit racing crossmember for G body's work with our turbo 6 exhaust systems?
2. What's the best way to lengthen the shifter linkage?
3. I have the electronic display speedometer, is there a way to skip the cable and somehow use the signal from the trans?
4. I bought the TCI BOP engine to Chevy Transmission adapter, Will the trans have any fitment issues?

Thanks in advance.



Plays with Fire
I know its a lot stronger trans, but how much more HP are you going to lose through the driveline trying to turn that monster? I'd imagine it'll be substantial.
Well, according to Jake's performance, the 4l80e weighs 178lbs, that's about 50 more than a TH350. Power loss is supposed to be less than what one would imagine, a few hundreths in the 1/4. I'll gladly loose that to improve reliability and not to mention improve lap times with the manual mode.

Here's the plan, the car is going back into the body shop for a few touch up's hopefully this weekend, not sure when it gets back, maybe a week or 2. In the mean time, I'm hoping to get the 2 lifts moved and installed at my buddies new house to make this conversion easier, otherwise I'll do it on my back. The idea will be to bolt the trans up, support the rear with something and figure out a solution for the crossmember and shifter linkage. Once I know for a fact it will work, I plan to buy some controller for it (not sure which one yet, maybe the new TCI) and get the drive shaft made. After I get it driving, I'll figure out the speedometer deal. There are currently 2 solutions that I know of so far, one cost 400 and the other 500 (TCI cable motor deal and Jakes Performance mechanical speedo drive). This will be a slow process but I will try to document and photograph it the best I can to help anyone one out down the road.



The 4L80 has a 5v square wave output signal that you can get from the transmission input shaft sensor (TISS). It's no different than any other Hall-effect sensor and will work with most aftermarket speedos that can be calibrated...
Hey guys, I know it's been a while, so I figured it's time for an update. The car is still at the body shop! Someone put a big dent in the passenger quarter panel and it's gonna take some time to get it fixed properly. I hoping to get it back mid August since the shop is really busy. Either way, the fiance bought me the TCI EZ-TCU and it'll be here friday. It looks like I'm just gonna buy the 4L80e crossmember from summit racing that's made for the g bodies and pray it clears the exhaust. With these 2 parts I'll have everything to get it bolted up and then figure out a drive shaft solution.


Thanks for the tip, I'm got the measurements from the G force (summit) cross member and I'm going to check to see if it will work with my exhaust. I have seen the Iceman before but I'm worried about it's strength....

Guys I know it's been a while but I haven't had the best of luck. I broke my wrist and the car is still in the body shop (couldn't help work on the car).... the new quarter is on but still not near complete. I have all the necessary functional parts for the conversion except for the x member, I actually bought another stock one to try and modify since I'm worried about the iceman's strength. I figured many of you might think I'm BSing on this project so here is a pic of the car from a few days ago.... I was hoping to get the car done before my wedding this Saturday but it's not looking good. I'll be out the first half of October, then I'll be 100% on it trying to get the car ready for the open track day in early November we got invited to at Austin's new F1 track. I'll keep you guys posted and I apoligize for the delays.


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I understand about the Iman strength ? I read a post on Montecarloss.com site from member saying his had a good bit of up/down flex. So a modified Stock one or the old heavy G-Force style may be a better option.
Good luck with the wrist rehab.


Active Member
I installed one. Buy a TCI adapter plate for like 80 bucks, bolts up great. Using the adapter plate you need a custom converter made that is a big bigger to compensate for the plate.

You do need a new crossmember, I used the g-force one but can't suggest it for a turbo car at all, its just not ideal. It fits and is beefy as hell but has two notches for dual exhaust, ie ss monte. The second notch isn't an issue (drivers side) but the passenger side doesn't line up at all for the downpipe. Only way to do it is to have a custom exhaust starting with a custom downpipe back

Electronics wise you need a few things, electronic speedo, and a bit of wiring for vss etc. Works great though and fits with no issues in the tunnel


For the shift linkage, here's a picture of the mods I had to do to put an 80E into my 81 Malibu. I was under my 87 GN today to check out the linkage and it is effectively the same and the same simple mods should work:


I see this thread is a bit old but there must be other people out there interested in the shift linkage mods for a clean 80E swap. I love this tranny and have a set of Twist paddles ready to install.

Hey guys, thanks for the pics. Chuck I would definitely be interested in detailed pics. I'm finally getting the car back on Monday and plan on starting the swap. It seems that you two guys already solved 2 of my 3 big concerns, the linkage and the crossmember, I still need to figure out the adaptation of the factory digital speedo. Hopefully I'll start posting pics soon to help anyone doing the same swap.
Yeah, but my understanding is that I may be able to tap into the vss in the factory digital dash with the speedo output from the tci ez-tcu and set it at the 2000ppm. Anyone ever done it this way?