I've done some digging...looks like the 2008 trucks came with t-cases RPO code "NQH" for Gas Engine Transmissions and "NQF" for Allison Transmissions if my research is correct.
NQH = MP3023/3024
NQF = MP 1625/1626
Both of these units feature electronic shift controls.
http://www.gmpartsgiant.com/componen...mn8k20743.html
I'll try and decipher what the MP part numbers stand for as far as input spline count, etc.
I may be wayyy off here, someone please chim in so we can learn haha.
Well I've found an article that shows a 2008 2500 suburban with a 6.0L engine, 6L80e tranny (should have 32 spline output) that uses the MP 3024 tranfer case with the dial selector on the dash: Motor Trend Article Page 4
I also found this magazine article that lists specific DTCs of the MP 3023/3024 tranfer cases: Transmission Digest Article Page 18