We have the same truck, the very last of the 5.9s, and we plan to keep it for a long time. As stock, it has enough power for our needs, so I've focused on reliability. How many miles on your truck and 6 speed or auto? I've done the following: 55 gallon Titan fuel tank, Dyna Trak free spin front hub kit, Fass fuel pump, Bilstien 5000 shocks, completely updated the front steering, updated the clutch, changed the front alignment specs (which helped a lot), and added a 20" Black Oak LED light bar to the front (which helped immensely when driving through Eastern Oregon and out our dark county road).
