The OTIII clutch provides a combination of exceptionally low moment of inertia, strength, and cost. Because of their low mass, it is not recommended that they be slipped, as in driving the car onto the trailer. Taylor Race Engineering can help you match the correct clutch to your needs. Formula 2000, Formula Ford, and other cars using stock-type Ford flywheels need to add the Heat Shield, #350-617. PLEASE NOTE THAT CLUTCHES DO NOT INCLUDE DRIVEN DISCS.