Flywheels are made from low carbon, hot rolled steel that is highly resistant to warping and perfectly suited for the friction materials mated to them. Single mount CNC machining guarantees precise tolerances and perfect balance exceeding O.E. specifications. Extensive field-testing has been done to determine the proper weight for each specific vehicle and to ensure smooth operation, safety and durability under extreme operating conditions. This flywheel can be used with OEM clutch kits but is recommended for use with Southbend clutch kits for better damping of clutch engagement. OEM clutch discs do not feature springs and clutch engagement can be very rough. **Due to the nature of lightened single mass flywheels added "NVH" or "chatter" will or may occur during operation. Accompanying modifications can also increase or decrease the amount of "NVH" or "chatter" in the drivetrain. Please contact our sales team with any questions.**