Has anyone had any experience as to whether a 6L80E will fit into a C3?

 

Not firsthand, but breakout the sawzall, it's a huge.

 

 

200r4 or 700r4 will fit better. a 6l80e will require a complete new floor, crossmember moved, eletronics, its not worth the hassle

 

How much torque you talking, as there's smaller 6L45/6L50 versions too. Agree, you're probably best going with mentioned 4 speed auto's. I went 700R4/4L60 on a few cars, and would probably go 4L60E now. The computer pricing has come down, and dialing in the TV cable, shift points on the non E can be a pain.

 

Agreed!

 

I am in processing of installing LS3/6L80E into my 1968. I did some initial fitment. I believe it is going to work. At worst, I am going to cut some fiberglass.

Please note that if you pick this transmission, you may need a custom built engine harness. I had to order mine from Speartech. You also have to figure out your shifter(G8, Corvette etc.), cross-member, drive shaft and new custom center console.

You can see find some info about my project here:
http://www.c3ls3.com

 

hmmmm - torque is 650??? will have to verify.

I will check into the 4L60 opportunity.

 

650 ft/lbs, of course you already know that's going to exceed the rating of just about any factory car transmission ever built. Sounds like you're on the right track with the 6L80E, as strong large output shaft unit. Not familiar with the mentioned Speartech TCM, but know GM Performance also sells a retrofit unit/wiring harness package. Not cheap, but if making that kind of torque, guess it's a familiar thing. Sure Culley's GM Parts House can help you out with the TCM package. Josh at Custom Image in SD can help out with just about any conversions too.

 

I just installed 4L80E in my 69 with no fitting issues, had to make new crossmember but that is not a big deal making a new one.

 

Gents....

I will check out TCM and Custom Image....

A 4L80E w/no cuts??? ...nice. I assume all computer controlled ? I guess the 6L80E is just massive in comparison.

 

if you want you could go full manual 4l80 and shift it yourself. I put a full manual 4l80 in a street rod and its bad ***.

 

Actually TCM just stands for transmission control module(computer) and not a brand. Custom Image(Josh) is an actual conversion shop though, and he's at 507-581-3076. Also curious to hear more about what you're actually doing, as lot's of torque, and gonna need some beefy drive line.

 

There is a member here that has installed one in a turbo BBC car, don't remember his forum name. He has a red chrome bumper car I believe but I don't remember much about the install.

I had asked about the computer he was using to control it and I think the price for the computer was around $1000.


Neal

 

oops - will check out Culley's... thanks

Well - I need to decide on another setup other than my TH400 w/Gear Vendor - so I am checking out various things.. oftentimes feeling like I am going in circles... and spending more time/effort.

I need the extra gears - no doubt. Always having an automatic, I liked the very firm, quick gear change, always consistent RPM peaks and never worry of missing a gear. Now that I check into various possible opportunities (2004R, 7004R, 4L60E, ...6L80E), I now find myself surprisingly open to a manual... which has me again pounding the square peg in the round hole so maybe 1 more "1 more" gear (so RS600 or T-56 Magnum or Viper Tranny....)

BTW - in onbe of the various threads I started (trying to keep topics separate) a CF member said something to the affect that who cares about microseconds on shifts - most of us do not race anyway... he was/is correct - expecially in my efforts. I nice shift w/ a manual will indeed do the trick these days for me. And I think if I ever started back to autocrossing (never was a strip guy but enjoyed getting on the freeways), the manual would be an advantage.

 

Well...NOW we're talking!!

Nothing like having *3 pedals* and *variable stall speed*!!

But what was wrong with Gear Vendors setup? Those things seem to hold insane HP?

JIM

 

Can someone school me on the 6L80E ? I 'm guessing it has 6 speeds but whats the advantage over a 4L80E? Different OD ratio? Different 1st gear?

 

I understand the gears on a 6L80E to be 4.02, 2.36, 1.53, 1.15, 0.85, 0.67

Jim - Am I finally coming to your side of the fence? Maybe so... the GV itself is fine - but really effectively offers an OD. Playing with interim shifts is not user friendly. Plus it is 2 hard shifts and one necksnapper to OD. The downshift is rough as well. My main complaint is the hack on my tunnel. I just want it out of there and restore my tunnel. And gee - its only .78. For the $$$ , work and time spent, I could have a T45 at least.

Jim - I need to follow up with you from the Fredericksburg trip - will PM ya....

one tranny I did not mention... was the Richmond... wil investigate as well.

 

Think you're beyond floor cutting concern, for the driveline stress levels you're doing. Best thing about the 6L80E, is being able to run moderate rear axle gearing, and get stellar highway fuel mileage. While not autos, owned a few late model Vette's with T-56's, 3.42 axles, and 70 mph highway cruising is 25-30 mpg all day long. Pretty nice with today's fuel prices.

 

Have 69 Vette with 572ci - 820hp + 2/kits nos. Originally had M-22, switched to Richmond 5-Speed, then switched to G-Force high HP T-56, experimented few different clutches including Mcleod adjustable soft lock and street tween, was not happy with it on Street or Strip and I do drive my car on the street often in nice weather, occasionally make few passes at 1/4. With clutch its nice driving on street but in heavier traffic with big cam it's no fun at all and I just got tired of it. After a long debate and research I recently installed 4l80e custom built by CK Performance with trans brake and manual valve body rated at 1500hp, and it has engine brake when shifting in lower gears. With heaving 411 rear end gear and 28'' tires I chose first gear 2.10, second 140, third 1/1 and od .75. I used B&M Pro Stick shifter and with slight modification of center console it fit's nice in stock location, and had Jason at Coan build me converter that stall's around 3200 rpm. Didn't have chance to take it on track yet but on the street I absolutely love it, no more jerking back-and-forth when stuck in heavier traffic and it's a lot easier on the motor. Shifting it manually with manual valve body and having engine brake when down shifting you get the same feeling as you would heaving clutch and you don't have to worry about clutching.
Best modification that I have done to my car with my engine combo was switching from clutch to 4l80e with manual valve body.
I know that Jim (427HotRod) prefers stick/clutch but with this combo it's even more fun driving on street. Personally I'm enjoining it more than when I had clutch and should be no comparison for 1/4 track, a lot easier on parts with better 60' and should run faster ET for shore. Will keep you informed as soon as tracks open up around here in the Northwest.
-Paja