i went with these because they were the step up from max .500 lift springs. with my .508 cam i didnt want to take a chance with coil bind or maxing out the springs and having premature failure.
Oldkimmer is correct. If you have a spring that will take .600 lift and you are at .508 lift you are too far away from coil bind. You need to be closer to coil bind than you are. If you do a search for spring surge or even search for high speed video valve spring or something like that you will see what happens when you are set up like you are.
