Mike B. said:
I would call TST and ask Mark what he thinks. Not all stock transmissions are the same as far as QC goes. Some have better castings than others and will hold more power before letting go. the problem is that you will never know if you have a good one until it holds or lets go.
On my 06 truck I've never used the TST over 4x4 and I can feel the transmission starting to get tired of holding the power. most of the time I keep the box set on 2x2.
Have your friend call Steffan at DTT to see what he needs. Before he calls he needs to know how much power he intends to put through the transmission.
good luck
Mike