I posted on LS1Tech to see if anyone there would find this info helpful, but didn't get much response. I know you guys have a bunch of LT swapped cars, so maybe it would be more useful?

Is there any interest in a parts list/writeup for swapping a 4L80E into an LT car? When I was doing mine I found a few threads from guys with an Impala SS doing this, but there was practically no documentation for F-Body cars. Mine Specifically is a 4th-gen 94 Firebird Formula, but I would assume many of the parts/procedures would be very similar. Tho I have never worked on a 3rd gen myself, I've watched quite a few videos of others working on them, and it looks like all the areas of the car involved are the same if not very similar.

 

I do not have a list of Part Numbers on hand at the moment, but...
There is not much involved.

This is a 1994 F-Body that has a Gen-2 SBC and a Early design 4L60E?

First off, the 1996 and earlier 4L80E Case fits slightly better than newer Cases.
This is because both Cooler-Lines are at the Bell-housing on the 1996 and earlier Cases.

Some room is needed to be made in the tunnel for the Electrical Connector... but not much.
Spohn, BMR, and UMI all offer a Cross-member for a 4L80E.

No Adapter, Crank-Spacer or special Flex-Plate is needed.
Use a Flex-Plate for a 1991 - 1997 G-Van with a Gen-1 SBC 350, and a 4L80E.

I am not certain which PCM Models would work for the Gen-2 SBC EFI/ Management.

Have fun!

 

For the 3rd gens you are own your own to buy a tunnel mounted torque arm or fab something yourself. I think the 4th gens have a crossmember / torque arm mount combo to buy. Other than that, the newer trans need some clearance for the rear-most fluid port and your are on your own for controlling the trans functions based on ecm. There are alot of old threads on this subject through the years.

 

Some 4L80E models are really close in wiring to some 4L60E models. A tune is still needed, but with a little wiring work, and tuning, the same PCM can be used.

 

Hooker makes a double hump crossmember with TA mount. You can literally install any transmission with that crossmember if you use the right trans bracket. I've got one in my 91 with a 4l80 and 370 LS. I had just enough clearance for the rear cooler fitting using -6an PTFE lines and electrical connector on driver side. You could also use banjo fittings for the cooler lines