You guys all know a lot more than I do so I like to confirm tumors with you before I go spend money. I've got a 2008 6.7 Cummins. It rides ridiculously rough. My family hates riding in it. My buddy and I looked at the coil springs and they are stock but he noticed that they have one more coil than on his 2005 5.9. While he did research he was told that the 08-09 were kind of trial and error phase for suspension with the new 6.7 engine. And my buddy was told that if he got coils for a 2006 model and put them on my truck then that would fix the problem. I just wanted to ask you guys what your opinions are. Thanks in advance!!