hmmm... maybe ill just have to go the 80e route... im not trying to have to change the T case too.. as obvi the 80e swap is pretty straight forward. and really not trying to have the truck down any longer than absolute nessecary. thanks for the input guys!
I think an 80e will be the most straight forward and if built and tuned correctly will hold a lot of power. I feel like the TH400 is a little bit of a fad right now. There is absolutely no doubt that the built TH400 is a stout trans, but overdrive is nice for daily driving and GVs aren't cheap. You could also go against the grain and get Kenny to build you a strong 60e. His are proven behind some very powerful trucks. Chevrolade, o2camaross and Jansen are some crazy power hungry fellas(Good thing) so they are going the route they have seen proven by the fastest LS powered street truck in the world. From what I know of yours build a very well built 60e/80e is the way to go.
ECSB 2kSierra 2wd 4.8L-K&N-HPtuners-Calspeed LT's-Magnaflow-Tahoe20's-HankookRH06
waiting to go in... 3.90s, 214/220cam