One weakness in the 2nd generation trucks involves a marginal intake air filtering system that quickly becomes a bottleneck when even relatively simple power mods are made that require more intake airflow. On my own truck, the simple addition of an Edge Comp added enough airflow demand to pull down the intake Filter Minder by two-thirds on the first RV tow up a steep Sierra grade - NOT good!

My fix at that point, was to provide a larger opening into the stock airbox to supplement the one DC provided - here's the stock box, and the stock intake opening from the passenger side fender area:





And here's the reinstalled modified box after drilling 5 2-inch diameter holes in the case:



The added holes provided enough improved airflow to prevent sucking down the Filter Minder from that point on - for even better airflow, I later also added a K&N filter that provided even more airflow.

This will undoubtedly stimulate comments concerning the K&N, but I've used them for MANY years on a wide variety of vehicles with excellent results - and there are other brands out there as well - in any event, the drilled airfilter case just by itself greatly helps avoid air starvation to the Cummins...

And when THIS mod is no longer enough, there's always the BHAF!