Quote Originally Posted by RedHeartbeat View Post
balance the valvetrain? Thats a new one on me, what do they do?
Balancing means that they operatively engage each valve (intake and exhaust) to account for manufacturing tolerances and other factors, by balancing the motion of the valves (opening and closing) because of the addition of the stiffer aftermarket springs. Once the valvetrain is balanced, it provides a smoother functioning and operating setup.