Im realatively new to the cummins world having bought my 08 6.7 2500 last december. Ive got a 36' 5th wheel and with the 35s on the truck it is a little uncomfortable to pull. Im looking to buy a used 1 ton dually just for pulling the trailer. From what I understand about the 6.7s i think it is better to have an 08 than an 07.5. I was just wondering if there are any 5.9 year models that are known to have problems even though they seem to be more reliable than the new epa6.7.