INFERNO Fury EXTREME DUTY Racing Clutch This clutch can be built in several different configurations giving the racer the ultimate control possible over their unique racing situation. Adjustability comes from the ability to change the engagement speed by changing the springs. With four shoes, racers are able to mix and match spring configurations, keeping in mind that clutch balance is important. For example, you can't set a heavy spring opposite from a light one. With the included black springs installed, this is a great clutch for Box Stock blue plate and unrestricted. Install the included white springs for restrictor plate engines with red, silver, or purple plates. Choose Drive Gear Size of your Choice from Drop-Down menu.