Regardless of which tuner, intake or exhaust you may have- You still need to dramatically increase your airflow to your motor in order for your diesel rig to get you where you want to go with ease and fair fuel economy.
It's easy to see why CFM+ manifolds flow over 40% better then the stock manifolds due to it's flow restrictions in multiple locations

DODGE CUMMINS INTAKE MANIFOLD:
The CFM+ intake for the Dodge Cummins offers up 44% more air flow than your current stock intake manifold. Its high strength, high temperature, engineered composite material has a heat transfer rate of 900 times less than cast aluminum. This means that not only are you going to get the highest flow of air, but also the coolest. Lower EGTs, higher performance, and better fuel economy, places this intake manifold ahead of the pack in today's growing diesel performance market.