Here you can see that both the fuel filter conversion and CP3 are fully installed. At this point, it was simply a matter of reinstalling the lower and upper intake manifold, intercooler pipes, air intake and then checking the fuel system for leaks. Prior to firing up the truck, a custom tuning file from Gearhead Automotive Performance was uploaded to the PCM. A custom-tailored calibration is a requirement with dual high-pressure fuel pumps in order to control rail pressure. Specifically, the amount of flow being commanded needs to match what’s needed.