4L60e

The 4L60e was the automatic transmission option available for 3800 equipped F-bodys. You can find this in 1996-2002 Firebirds and Camaros.

The 4L60e is a very common transmission among GM rear wheel drive cars, trucks, and vans from the late 80's - early 00's. Earlier models were actually known as either a 700r4 or a 4l60 instead of a 4l60e. The earlier models without the “e” designation were not electronically controlled.

The 4L60e had a few different bell-housing options, and earlier versions did not have a removable bellhousing. If you're trying to use an early 4l60e variant you will need to make sure it has the right bellhousing. 1998 was the first year the 4l60e came with the the removable bellhousing in 3800-equipped vehicles.

Below is a side-by-side of both transmissions:

There were a few differences between each year for the 4L60e.These are all pretty well documented for most vehicles the 4l60e was shipped with. There are a few differences between the 3800 version of the 4l60e and the v8 version.

This video helps to explain most differences:
https://www.youtube.com/watch?v=An2tp8uo3Fs&feature=youtu.be

Generally it is widely accepted that the “V6” 4l60e is not as strong as the v8 version and there is actually quite a bit of truth to that. When people refer to the “v6” 4l60e though you will want to look out for references to the 4.3 v6 version since it is going to be very different from the 3800's 4l60e.

The 3800 4l60e has a different input shaft, torque converter, bellhousing, pump stator tube, second servo, forward accumulator spring, 4th accumulator spring, and likely a few other things.

This image shows the differences between the v6 and v8 input shafts:

Interestingly enough, the 3800 4l60e is very similar to the 4 cylinder s10 4l60e's. The 4 cylinder engine in the s10 has the same bellhousing as the 3800 and also shares the same input shaft.
The s10 transmission is interesting though because the s10 converters have a higher stall speed than the 3800 but externally are exactly the same. You can use the s10 converter on a 4l60e to get a higher stall speed as well as better launches, but the trans will feel like it's always slipping.

The 4l60e is kind of a mixed bag here. People have reported many different results with it. Generally though you can get away with throwing a decent amount of power through it without issues. The 4l60e definitely has its weak points though and it is heavily documented all over the internet. With some upgrades, the 4l60e could probably handle most builds that aren't too extreme.

Generally though the transmission is known for not shifting well when there is a lot of power going through it.

As with most automatics, a transmission cooler is recommended to help keep some life in the transmission.

Referrences:
https://ls1tech.com/forums/automatic-transmission/1299642-will-v6-4l60e-bolt-ls1-if-i-change-bell-housing.html