I was wondering if anyone has some specifics on what it would entail to install a 4l80E in a 3rd gen?? I have spoken to a few people regarding this and I am getting conflicting responses. Some people tell me that the tranny will not fit in the tunnel. Some say it will. One person told me that I will need to fabricate a crossmember, shorten the ladder bar/reconnect to the crossmember and shorten the driveshaft. Lets not forget the aftermarket ECU to control the transmission if i decide to run it that way. Can anyone give me some definitive answers regarding this swap?? Anything would be greatly appriciated. Thanks

TH400 fits. Crossmembers not a problem with spohn torque.

Don't know how much power your making but a properly built 2004R will live
in the mid 9's

I hear what you are saying and you are right. The only problem is that I am on the border line (Approx. 950 HP). So far the car has ran a 9.6 @ 145 running 18 LBS (T-76 ball bearing) with lots more to go. I have been playing the 2004R game for a while (in multiple cars) and I need something more stable. I am sick and tired of rebuilding the unit every season. The car is a street car and I am not willing to give up the OD, so the T400 is out of the question. I was considering the Gear Vendors/T400 solution, but I cannot afford the room with my 4 inch exhaust being in the way of the Gear Vendor pan. So the only option seems to be the 4L80E. Thanks for your input..

So obvoiusly you know what you are doing and are a member of turbobuick.com why ask this ?? here, when you can just talk to Bruce (We4) over on tb.com,he can build it right...

Is the bellhousing bolt pattern even the same? The 4L80E is only available in the Chev V8 pattern unless you use something like an Ultrabell.

The 4L80E is a big, heavy tranny. In stock form it can handle about 500 pounds of torque. It has the same gear ratios as a TH400 but also has the 0.7 OD gear.

The information you already have is correct. It's much longer than a TH400 so crossmember, torque arm and tranny tunnel modification will need to be done to make it fit. Since you're running in the 9 second range, you'll need a flexplate and tranny shield which will make clearance even worse.

A complete well built 4L80E with computer should run you $3000-$5000 not counting what it's going to take to install it.

Anything can be made to fit. Just don't expect it to be an easy bolt in job. Changes and modifications will always be required.

A 4l80e is a large trans. It should fit a little better than a 400/gear vendors combo, but will require about the same amount of work to install.

The 4l80 will have a lock-up tc, which a t400/gear vendors combo will not. You can also get a manual valvebody, thus eliminating the need for the ecu to operate it, but making it less street friendly.

You can also get a reprogram for the 4L80E to make it a 6 speed. Not a cheap kit but allows the engine to stay in it's powerband longer. Best for trucks pulling loads up a hill. You don't have to downshift a full gear.

1-1OD-2-2OD-3-3OD instead of 1-2-3-3OD

No I don't have it on my truck. Even pulling my race car on the trailer I don't have to drop out of OD going up hills.

Get a good used 4L80E for a core.

Swap that out to a vendor to build.

Run a later model TBI pcm with trans/eng controls and blank out the engine stuff.

U need to run vss,rpm,tps,map to the trans ecm from your original(what r u using?)

Now u have a controller for about $200, less if your crafty.

later
Jeremy