this one can go either way, stock or mod forum but im putting it here, i pulled up next to a brand new 450 merging on the freeway in SLC today and i got on it a little and the guy in the 450 kept up, he finally passed me and when i was behind him he romped on it and a pretty good amount of black smoke came out, about the same as my powerpup on 40%. ive only driven an 08 f350 with the 3.73 once and it was pretty quick i guess but this guy was moving, i dont know if he had the 4.30 or 4.88 and i dont really have an idea how much more passing power they have but could he have been testing a chip for someone, he was an out of state guy? or is his dpf not working right? or is there some middle ground, i thought the dont smoke AT ALL but i guess i could have been mislead? thanks all im just kinda wondering what everyone else was thinking.