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I have been thinking about doing a LS/LSX swap with a 6L80E or 8l90e trans.(update) After other input I have decided against these and maybe go with a 4L80E.
I have a 496 with 400 turbo currently in my 71 chevelle convertible. I hope to find someone that has done the change with something similar. My car has factory AC, power steering and power brakes. I do not want to cut the trans tunnel or change the AC box but would consider the other things. I am looking for something with at least 500HP or more. Combinations, parts etc.
I doubt you'll be able to get away w/o cutting the tunnel, at least with the 6l80. You'd have to angle the trans down in the back and totally hose your driveline angles or...well, there really isn't an or other than cutting the tunnel as far as I know.
Yeah, those trannys are pretty big man. If you wanted to go manual, the Tremec TKX was designed with LS swaps in mind, and is much smaller dimensionally and is good to 600 ft pounds.
Youre going to be cutting out a huge chunk of the firewall and trans tunnel. Not sure if they make a harness to run a standalone 8 speed but there is one out there for a auto 6 speed. Theres a couple people in my facebook group Pro Touring Buildz that have done the 6l80e swap in cars.
thats a 4 speed. big difference.
i understand you not wanting to cut your car up, im going with a th400 in my chevelle wagon for the same reason, but a t56 mag, 6l80 and 8l90 are all much larger than the older units.
I put a LS3/6l80 in a 72 Chevelle and unless you want the trans hanging down a good bit you’ll need to cut the tunnel. I’m still hunting for a floor shifter. Good luck either way
I am not going to cut my car up.
This was done without cutting..
" LS2 with 4l70 out of a 2007 TBss two wheel drive in my 68 convertible "
A 4l70 is no different than a 4l60 in terms of casing size. A 6l80e is much bigger. To run ANYTHING that has more gears than 4. You will have to cut tunnel and or firewall. There's no way around it.
Just remember there are several ways to cut and raise your tunnel. You can merely cut a “ T” , “I” or event remove completely. With relief cuts, obviously you peel the metal up to clear the trans and fill in the voids
I added pictures as the reason I do not want to cut the car up. I guess maybe a 4L80e would work. I just thought it would be nice to have all the gears...
Yeah, that thing is gorgeous, so I can definitely see why you don't want to sawzall it all up, but that said, if it was done right, it really doesn't hurt anything, anyone looking for a 10 out of 10 restored vehicle like yours would be looking for a modern engine and trans. Not to say the 4L80 is bad, but like you said, would be nice to have all those extra gears and better fuel mileage.
I helped a buddy do a LS swap in a 69. We also put a 80e in it. He really didn't want to cut on the car, but to get the 80 in where it needed to set, it needed to trans tunnel cut up. His car is also a beautiful car. Cutting up the trans tunnel at that point really isn't that bad.
My car is a 70 with a LY6 / 4L80E combo. I used the Holley forward mounts and trans crossmember. I had to use banjo fittings for the trans cooler lines out of the trans from a guy off ebay that makes them. My car war originally a factory a/c car but i smoothed the firewall and went with vintage a/c but I'm sure the factory a/c box would've cleared everything. Also used a Holley Terminator X Max for the harness and ecu as well as their mid-length stainless steel headers.
I know others that have put the l80 e in and not cut the floor usually the lines are the problem. if you use the banjo fittings the lines are no longer the problem.
(QUOTE=rpturbo;20418369]I helped a buddy do a LS swap in a 69. We also put a 80e in it. He really didn't want to cut on the car, but to get the 80 in where it needed to set, it needed to trans tunnel cut up. His car is also a beautiful car. Cutting up the trans tunnel at that point really isn't that bad.[/QUOTE]
Chris,
that looks great... What combination was you running before? What rear are you running? How do you like your new combo? What would you change??
Those over the axel pipes look huge. Are they 3"?
Nice car redman! I wouldn’t cut that one up either. In my case, I knew what I wanted to do before I ever found my car, which needed floors anyway. I wanted a more later model looking interior, so my raised trans tunnel fit the bill perfectly. Stick with a 4 speed auto and you’ll be fine.
Thanks!
Previous combo was a 406sbc / 200R4
Rear is still stock 8.2 10 bolt with Eaton unit and 3.55 gears
I love the new combo it gets 20mpg with the a/c running on the highway
At this moment the only thing I would change is I would've liked to do a forced induction setup on it but other than that I love it.
It is 3" exhaust all the way out of the back, it is a Pypes exhaust kit that has been cut on and worked to fit. We have a guy in the area in the Monroe, GA area that does custom stainless exhaust and I had him cut the kit up I have and make it work.
The 6l80e is cool, but aside from the tunnel cutting there is the issue of controlling it, which means no Holley Term X Max (unless you spend another $900 on the PCS controller). I'm trying to find a 10 speed to look at in real life to see just how big they are. My tunnel is toast already so cutting would not be an issue.
I put a LS3/6l80 in a 72 Chevelle and unless you want the trans hanging down a good bit you’ll need to cut the tunnel. I’m still hunting for a floor shifter. Good luck either way
You can use the stock-style horseshoe with a shiftworks kit, works pretty well if original look is something you like.
02-16-2022, 03:38 AM
Chevelle swap to LS/LSX 4L80-E Help 
