Diamond Eye Manufacturing K5164S 2011-2012 Chevy/gmc 6.6l Duramax 2500/3500 (all Cab And Bed Lengths)-5in. 409 St DIAMOND EYE PERFORMANCE K5164S KIT, 5IN, DOWN PIPE BACK DPF-RACE, SGL 409 SS 2011-2012 6.6L DURAMAX