either truck will do, the duramax is better , for towing. in 2004 I bought brand new Chevy 2500 with the Chevy 4 speed auto crew cab, I put 32,000 thousand mile on that truck 6.0 liter 4.11 gears it ran good, the ave milage from the day I bought it was 9.4 mpg. In July of 07. I bought the same...