Competition Clutch flywheels are made of 4140 forged steel and are a one-piece design. This helps significantly in reducing the chances of ring gear separation and friction surface warpage. All flywheels can be resurfaced. The correct flywheel step can be obtained in the CCI catalog or by calling us direct. Flywheel weights vary from 8lbs to 18lbs depending on application.The lightweight steel flywheel (ST suffix) is recommended for naturally aspirated and/or street driven applications. This flywheel preserves low-end torque and driveability. Well-suited for Gravity, Stage 1 and Stage 2 clutch applications.