IF you want performance mods or want your ole' Cummins to purr like a kitten get in touch with Garth at Full Throttle in Rocky Moutain House. Been going to him for years now with my 2007 5.9L you can't beat his service.
Yeah K&N and diesels don't really mix well together, to much gets through with the amount of they suck in, silicon levels in oil analysis jumps up real quick.