Originally Posted by bowhay
looser valve lash will give u more top end, tighter will give u more torque of the bottom
This advice given above is exactly wrong. More lash gives less duration and tighter gives more duration. More duration will enhance the top end and likely remove some from the bottom end. You must respect the manufactures intended valve lash and not deviate more than .010" either way, too louse a setting will hammer the lifter off the lobe causing damage.
Bruce