I am putting an '04 LQ9 in my '70 Impala, and I will use a 4L80E from an '05 Savanna full size van which had a 4.8 engine. I need some directions about this tranny:
Are all 4L80Es the same inside? If not, what are the specifics of mine, how strong is it?
Apparently, not all 4L80Es have the same converters/stall speeds; what do I have?
For a stock LQ9 with an LS6 intake and a cam, should I change the converter? How good/useful/fun is a shift kit? Can I change the shift firmness through the computer, or is this only a mechanical mod?
The car is about 4000lbs, will be a nearly daily-driver in the summer and see some bracket racing; I want the car to be fun in traffic (no high stall).
Thanks for any comment, input...

 

You can change the line pressure in the computer which will increase shift firmness. I think GM rates the 4L80E at 480ftlbs....that's what a guy at Hughes' told me yesterday anyway. I'm not sure if thats motor or at the wheels, but most say a stock 4L80E will hold 500+rwhp without a problem. I'm a shift kit, and deep pan will be the only mods mine gets.

 

I don't think the 4L80E has servos at least not like the 4L60E does.

 

edit

 

I would think a Savana with a 4.8 would have a 4L60-E. The bolt pattern of the pan on a 4L60-E is a square. The pattern on a 4L80-E looks like a tombstone - curved at the back.

There have been changes made to the internals of the 4L80-E over the years, but the last significant ones were in 1999 where the width of the gears changed, and in 2001 when the roller clutch changed to a better design. In general, all 4L80-E transmissions since then are interchangable.
The 4L80-E has two "servos" for two bands, but these bands are only used for engine-braking overrun and for reverse. The best way to improve shift firmness is through the use of a shift kit that increases the volume of the supply fluid rather than increasing line pressure through programming.
If the Savana trans turns out to be a 4L60-E, I would seek a different solution.

 

James,

I have seen a 4.3 van with a 4l80e in it.... so it wouldnt surprise me if it is actually a 80E.... I dont understand it, gues they are scared the awsome torque of the 4.3 will be too much for a 60?????

 

Wow, cool. I guess the van guys are smarter than the truck guys.