I know there is probably a thread already about this but i can't fine it, so here's another one. I have a GMC 6.5L Turbo Diesel with 161,000 miles on it, its a turd, i don't like anymore. Its a dually, but it just can't pull like i want it to, so time to upgrade!! Im looking at the cummins 5.9 because everyone i know loves them and they pull great. Do you like they way they pull. Auto, or Manual?? What do you think??