Actually, Adrian.. The auto is the way to go, the auto is rated for quite a bit more torque than the manual... However, the real way to go is to do a Allyson swap, which costs about 5k$... If i could find a truck that already had an allyson swap i would be interested.. Or that may be a project down the road for me...A good friend of mine is a certified Cummins tech, so if i ever need any help i can call him he use to work on those motors daily in the marine core, before he went officer..