Recently purchased a 6.0 out of a 03 Hummer for my 64 conversion. It orginially had a 4L80 trans which I did not buy as it was for 4x4. I am aware that it could have been converted but I really dont know much about transmissions in general. My question is what year of trucks should I look for to get one of these? Also does this tranny have a TCM or is it intergrated into the PCM? As said I'm not very familiar with these, just trying to go the simpliest route.

 

'91 -'96: They are all pretty much the same. They were also known to have a crappy connector that passes through the case. Most have had them updated by now, but there are still some that haven't and might need replacing. They have the ‘older’ style lubrication, where both cooling lines are behind the bellhousing. They also have larger overdrive roller clutch, usually came with a 16 element sprag instead of the 36 element. The bellhousing bolt pattern is the traditional SBC/BBC pattern. These early transmission also did not have mounting holes for the manual lever position switch (MLPS) ie. neutral safety switch.

'94 -'96: These are the same as the earlier ones but with a few differences. It has an updated EPC (electronic pressure control) solenoid. Some also had a longer shift shaft for the MLPS.
'97 - '99: These years have the ‘new’ style lubrication, where there is one oil cooler line behind the bellhousing and the other being farther towards the back of the transmission. Also uses the bellhousing bolt pattern of previous years.
‘00 - ’03: Same as previous years but bellhousing bolt pattern was changed to the LS style.
‘04 - up: Same as previous year with some minor valve body changes.

I would get a LS 4L80e (00'+) as they have all the updates, cooler lines, bellhousing, valve body, etc. I am personally running a 05', picked it off of CL for $50, but needed a rebuild.

The 4L80e is controlled by the PCM, it doesn't not need a separate TCM like the 6L80e does. Since your 6.0L already had a 4L80e, you shouldn't have to re-pin anything, however there is a different slight difference how the VSS works in a 2WD vs 4WD. 2WD uses a input and output VSS's in the body of the transmission, the 4WD uses the same front VSS as the 2WD, but moved the output VSS to the transfercase, instead of the rear of the 4L80e like the 2WD. Both will work, however the reason why the 4WD output VSS is in the transfercase is so it can tell the ECU if it is in 4H or 4L. If you use a 4WD 4L80e, you'll need to add a VSS in the tailshaft housing as the 4WD just has a dummy plug where the 2WD output VSS sits.

Not sure of the power levels your looking for, but I'd imagine you could probably also find a 4L60/65e, and stuff that in there and have similar results, however you'd need to swap a few wires for the transmission in your harness that feed the PCM. Hope some of this helps, good luck.

4L80e info

 

you also need a different tail shaft installed,housing and yoke. but not that big of deal. i found my pars used. you can go to the transmission center. www.transmissioncenter.net they have any and everything you could want for a 4l80e including things you didn't even know existed.