Well, he is bottoming out the piston in the lifter, making it a very deep 'solid' lifter. I dont know how the pushrods are going to like it but its viable although the solid 'lash ramp' is going to play havoc on his timing as its going to lift the valve early as the lifter is going to become solid again once the oil enters. Not what I would expect to hear from a lifter manufacturer....?