There are a few rummors that GM has a couple of new different tranny's that will be offered soon. Also heard that the 6 speed auto was a tranny that they were going to use in the 1500 series trucks at some point.They have tuners already for them, intakes, exhaust, etc.
For forced induction or more andvanced tuning im not sure. I dont know that they will be offering that tranny in the 1500 trucks....never other than the HD 1500 was the 80e offered before so doubtful as well on the new trucks.
Yours might have the 4L60E due to it having the 4.8L or 5.3L engine I would guess.I have a new 07 suburban. It is using the 60e trans. I would think the new trucks would be the same.