Is the new 6 speed in the 06 trucks a allison unit? If so what will be the benifits? Will it handle more power and Tq? Will it improve gas mileage? Will it able GM to get rid of the body lift? When will the 06 6 speed be avaliable? Trying to decide between the 05 or 06. The 6 speed sounds good if it has more versitility....Thanks