Why is it that when you nail it in 4-low it takes 2-3 seconds for the power to kick up ? and in 4H it's right there http://www.dieselplace.com/forum/smileys/Confused.gif maybee something to do with the torque ? My buddies LB7 doesn't do this ?

ALL Durmax truck will have less power in 4wd low. The ECM reduces the power to keep from damaging the transfer case, front axles and front diff. GM has been doing it this way for years so it's not new to the LLY application.