Monty

I haven't seen one in person, I don't think, but I hear they are larger than a 700R4/4L60. But most importantly, I hear they are nearly bulletproof. I know they are fully computer controlled - I'd get a stand alone kit for that - but need to know if anyone has any good info on whether it will physically fit or not.

Neo Fender

I think that the 4L80 is an electronic version of the TH-400, so I would assume it would fit.

gkull

Way back when I along with the tranny shop couldn't physically fit in the L80. It's what I wanted to because my neighbor had one in his 40's street rod pickup with IRS rearend.

I determined that you would have to cut out the tranny tunnel and re make it larger. So I didn't do it. If you set a 700 and an 80 on the floor next to each other you will know what I'm talking about. My 79 went from a TH350 to a 700 and it could use more room.

The other solution I looked at was placing the motor lower then a L80 would fit.

Monty

Do you remember where the tight points are? Wouls it be some that could be accomplished with a little messaginf with a hammer or are we talking major rework.

gkull

My 79 tunnel is fiber glass with metal only in places if I remember correctly. Like I said. It appeared to me that I would have had to take a sawsall and cut around the fire wall back on both floor sides and take the console out.

It needed the firewall and tranny body clearance. I wanted to do it bad. but at the time I just didn't feel the gains were worth it along with all the new carpet and console work.

Monty we need to get some insight from someone who has done a body off on your 82 . My floor pans are even fiber glass. I'm not sure what might have changed over the years because yours might have more clearance because of the factory 700R4 option.

I went to a large tranny shop and they had both types on the shelf and we looked long and hard at the options.

Stingy74

Aren't the motors set lower and farther back in the 80-82's? I can't confirm this but if so the 4L80 may fit with the extra clearance in the tranny tunnel.

vert2go89

From articles in mags I've seen the 4l80 will fit but you have to change the trans cross member position and shorten driveshaft.I don't remember why but it said the 4l80e will not fit.corvette fever mag had articles on this.

vert2go89

oops I think it was the 4l60 would fit but the 4l80 would not.

Apeiron

The 4L60 is essentially the same as a 700R4. The 4L80E is quite a bit bigger and heaver and I doubt it would fit. Plus there'd be the added expense of the computer to control it.

ddecart

Basically.....
The 4L60 is a TH350 with an extra (4th) gear
The 4L80 is a TH400 with an extra gear.

The 4L80 is the trans that goes into the 3/4 and 1 ton trucks. These see some SERIOUS duty out in the field.

That said, I have no clue about the size of the trans. I took the job in Vehicle Dynamics and not the one at Powertrain :D

Dave

Budman68

Some guy posted all this good news about Bowtie putting a 4l80 in vette a few weeks ago. Maybe its in archives or just give those guys a call. I hear they like to talk tranny conversions.
Budman

Budman68

Oh I forgot, Monty can I have your TKO when you swap. Why do want to swap anyway?

dsagers

I posted one of the messages about a 4L80E going into a C3. Steve Holmes of Bowtie Over Drives makes the correct crossmember and includes a relocated emergency brake cable bracket.
http://www.bowtieoverdrives.com/

Monty

So are you saying that a 4L80 WILL fit into a C3 Corvette? Do you know of anyone who has put one in?

I see some of you are saying a 4L80 is nothing more than an electronically controlled TH400. I was not aware of that, I thought it was a completely different, heavy duty OD tranny.

The reason I am looking at a 4L80 is that I am told a properly modified one will handle 1000+ ft lbs reliably. Short of going with a race only type of tranny this seems like the best option. Speedpro/FAST offers their T-COM computer, which allows you to calibrate the shifts and shift feel via a laptop, almost identical to the Speedpro/FAST SEFI system I have.

If it turns out that a 4L80 will fit, I will be selling my TKO. It only has about 200 miles on it works great. I also have the orignal shifter that comes with it, a custom shifter that properly locates the shifter in you stock console, a LAkewood bellhousing , flywheel, a brand new Centerforce dual friction clutch and pressure plate, all brand new clutch linkage, includeing 2 sets of the Speed Direct sherical rod end link clutch linkage, the hd tranny yoke from Forte's - about $3000 worth of stuff.

Monty

Well the owner of Bowtie Overdrives says the 4L80E will fit in a C3, but I'd like to collaborate that before I buy it. Anyone else know?

Budman68

Monty,
And I thought you liked me. :D I promise not to put to many miles on it. Good luck on the swap. I'm still tripping over my 700R4 in the garage and need to get motivated to put in.

Monty

Sorry Budman78,

Had to sell the TKO to pay for the 4L80E. I bought a brand new, still in the shipping crate 4L80E yesterday for $1450 off of eBay. They go for about $2500, including core charge, from your local GM/GMC dealer. Should have it next week, I've got to get it installed in a hurry, sicne my car goes to the chassis shop for the turbo headers and exhaust on Jan 5.

Matt M

Got to get it installed in a hurry? GOOD LUCK!!! That's a pretty serious conversion, but well worth it if you get it done right. I kicked around that idea for a while, but due to cost and work involved, I went with a modified 200 4R built by Jim Campbell in Ohio. This was a pretty easy swap (easier than 700 R4) and works great. When properly modified, the 200 4R is stronger than any modified 700 R4. If you plan on making over 600 ft lbs of torque, however, then you will need a 400 or 4L80e. Good luck with the swap and make sure you take lots of pictures and document the entire process. This would be some very valuable information for anyone else who might do this swap in the future- including myself when I build my next motor and run more boost. :)

Matt

Monty

All I need to do is get it bolted to the engine, just so they can make the exhaust pipes fit correctly. I don't have a torque convertor yet, so I probably won't even bother mounting the flexplate. I also won't even worry about the shifter or electronics. Depending on how things line up, I may have them fab a crossmember too.

When I get the car back from having the turbo headers, intercooler, and exhaust done, the motor has to come out anyway to swap the pistons, cam, o-ring the block, and rebalance the rotating assembly. Then we're dyno testing and tuning it. While that's being done, I'll get the convertor made, and install the T-Com.