Dyad Drive System Twin Disc Clutch Chevrolet LS9 Crate Engine;Input shaft: 1-1/8-26;Ring gear tooth count: 168;Ring gear outside diameter: 14.096;10.5 inches;No complicated setup or adjustments required;Fully dampened clutch system developed for vehicles with extreme power levels;Quiet, positive drive floater;Smooth engagement and light pedal effort;High torque capacity up to 1300 ft/lbs at the flywheel Centerforce Centerforce Dyad Drive System Twin Disc Clutch - 4614869 04614869 Clutch Kits