The LST Camshaft Series uses the newest and most advanced lobe designs from COMP Cams. These new lobes provide the potential for major increases in power and torque in Duramax engines when combined with the appropriate tuning. The Low Shock Technology features lobe profiles designed to maximize additional engine airflow, which reduces harmful EGTs, while improving stability at higher RPM. These profiles are also easier on the valve springs, enhancing durability and reducing load loss. Organized into stages that allow you to choose your level of performance, Stage 1 Camshafts are No Springs Required and run well with the factory or a performance tune. Stage 2 and 3 camshafts require a COMP Cams #26125 Beehive Valve Spring Kit upgrade but do produce the greatest potential for additional power and RPM when matched with maximum effort tuning.