Yeah I noticed the debris in the valley after I looked at the pics a little better, he did say he would have everything for it. The auto stuff is all knew to me but have to plan for the worst after all my T56 troubles. So wanted to try and stay ahead of it. From what I hear they took pretty decent amount of power, I did see there was a kit to beef it all up which I would look at when doing the transmission over the winterThat thing looks like a nightmare to get right. Robbed of key parts and no longer sealed; and full of debris. Run away!
550ish HP is a cake walk for any LS. No need to open it up beyond a cam and springs - especially for a Gen IV 4.8L as it won't have any DOD or AFM issues. The 4L80E conversion vs. the billet 4L60E is going to be an interesting debate... I went billet 4L70E in the TBSS for a reason: Ease.
I am not up to speed on the robustness of the SY/TY AWD system - but uber low end torque may not work well, especially with traction.