Change the fuel button in the back of your pump. But 290 has no aftercooler so be real careful. Once turned up you’ll have to watch gauges close.
Aftercooler has little to do with longevity. It is coolant to air cooler for the charged air. Increase the pressure, increase the heat. Lower the heat, increase the density of the charged air. Air-to-air works better than coolant to air, so that's what we have now. The problem with trying to squeeze horsepower is that the 290, unlike the higher hp Cummins had a modular crank as opposed to forged. Put too much to it, the crank is liable to snap.