i figured, if the rockers were lighter, the spring pressures can be lightened (when i go to a larger cam) thats how i kept valve train wear down when i hot-rodded air cooled vw's. i could run a much lighter spring in the motors i could spin to 7000-8000 revs by using the alloy rockers and titanium retainers. it made for a longer lasting street motor and less frequent valve adjustments.