What to get more out of your 6.7L? Using Hamilton Cams 1.5" Valves w/ Seats (07-h-006i) replacement valves over OEM 1.3 valve there is potential for 30hp+ on 6.7L engines. For a high-performance build, this is the most important addition after injectors tuning and turbo. For more power potential these high-performance cams lift the valve faster, optimize valve events and leave the valve open longer at higher lifts to get more air into the engine. Larger valves raise flow at every lift point and allow the max flow to be reached sooner and for longer.