8.8" DifferentialTorsen TypeFull Time Torque Sensing, Torque BiasingFits:31-Spline Axles2005-2012 Mustang GT2007-2012 Shelby GT500 Fits 2005-2012 Mustang GT and 2007-2012 Shelby GT500 with 8.8-inch axle and 31 splineFits 8.8-inch axle with 31 spline 8.8" Torsen differential2.7 bias ratio31 splineFeatures full-time torque-sensing, torque biasing differentialStandard on 2012 Boss 302 Mustang Laguna Seca packageWill accept anti-lock exciter ringThese Ford Racing Torsen differentials use a worm gear friction system that will not wear out like conventional clutch-type positive traction differentials. These differentials ensure your engine's power is transferred to the wheels with the maximum traction. The unique torque-sensing.