See below for filtration installed (installed within 10,000 miles of new in both cases). I just had someone check my injectors with a TECH 2 on the 03 since the 7 year warranty is expiring. The check showed that the injectors (return rate, etc.) are right on the money.
1) '03 GMC 2500HD Dmax/Ali Ext/Short 4x4; 4" exhaust, egt and boost gauges; exhaust brake; Bilsteins; BD exhaust manifold; Oil Guard bypass; Lubrication pre oem fuel filter; Tekonsha Prodigy; Mag-Hytec differential cover; Suncoast V transmission w/deep oil sump
2) '07 Classic GMC 2500HD Dmax/Ali Ext/Short 4x4'; Bilsteins, Silastic shackles, BD exhaust manifold; Oil Guard bypass; Lubrication pre oem fuel filter; Tekonsha Prodigy; Federico sway bars; Dipricol boost and egt gauges; Transgo Jr,, Mag-Hytec differential and transmission pan