I feel i should adjust the intake and exhaust valves on my engine although it only has 36K miles, I feel I should adjust them due to the vibration in the engine, it is not bad it is just not good and after reading the acceptable tolerences on the valves I feel I would like to get them dead on not kind of close, I figure it wont hurt, I ahve experience setting the valves on mercedes diesels but never on a CUmmins, is there any special tools recquired to o this or any tips or advice, thanks much.