1BadAction

iTrader: (10)

getting the factory crossmember would be the easiest thing for you to do. mechanical fitment is the easy part of the swap, IMO.

Bo185

The 6l80 has a 32 spline count(Same as the 4l80)!!!! The 4l60/70 has 27! You have to swap to the 32 spline input for the transfer case

The 6l90 is way bigger than the 6l80. With a 34 spline count

6l90 left 6l80 rt

1BadAction

iTrader: (10)

Holy ****!

That's why I was confused, I kept hearing that the 6l90 had a bigger spline than the 6l80, but the 6l80 was 32. I had no clue there was a 34s output.

My point in trying to nail this down (thank you, BTW) is that this makes the 6L90 not available to use in older 4wd vehicles with a floor shift, without some kind of exotic transfer case/adapter, or converting to AWD with a new case. I also asked about rebuilding the 6Lx transmissions, and there is nothing in the way of performance parts yet... So it looks like I am stuck with the 4L60 and gen3 stuff for right now.

05HD1500

Anyone figure anything out yet as far as going from 4L80 to 6L80?

pewterliftedz

iTrader: (4)

bringing this thread bak from the dead.
@ MNC5 hey man i was wondering what makes it necessary to switch fuel pumps.
is this not something that can be corrected by the tuner.
also do i have to use the PCM from the donor vehicle or can i reuse mine flashed with the new drivetrain?
My warranty will be ending soon on my NNBS and a LY6/6L90e/4wd TC swap are 1 of the first things on my todo list.

ButlerBoy

Anyone done this swap in a NBS yet? If so can someone put up a link to point me in the right direction? I'm a long time from being able to do it but would love to one day and have all the info I can to make sure it's done right. Thanks.