Originally Posted by Wezz
Hi yes they are stock springs But there is a spring inside the spring .. Is that normal? Btw they say on the edelbrockweb its also good enough to usr stock springs. With te performer plus.
The inner spring is called a "damper". Its job it to keep the spring from vibrating. At certain engine rpm, these vibrations can cause the spring to not work right, or to even break.
From Valve Spring Installation - Mopar Muscle Magazine
"At the bottom we have a typical single spring with damper, actually a factory 440 Magnum piece. This is not to be confused with a dual spring, above, which carries another true inner spring in addition to the main spring, and usually a damper."