Select the correct cam for your application. High duration cams are very impressive at the upper RPM ranges. However these same cams offer little improvement at idle or low RPM. Vehicles with automatic transmissions will show little improvement since the transmissions will normally shift to the next gear before the engine reaches the power band. For higher torque select a low duration cam with higher lift. For more RPM horsepower select a high duration cam. For street sport applications we recommend the cams, generally speaking, with a duration of less than 290 degrees. For track only applications we recommend the cams with greater than 290 degrees. Never use old or worn lifters on a new cam. Make sure the oilers are clean and free of debris.