Eaton 19559-010 Eaton Posi Limited Slip 30 Spline Differential with 10 Bolt for GM Car/Truck Virtually Bullet ProofPrecision-Forged GearsCarbon Friction TechnologyPrevents Wheel SlipAutomatic/Rebuildable * GM 8.5/8.6 in. Eaton Differentials Require Special Bearings* Axles w/Small Bearing Bores OD 2.89 in. Req. PN[LM-102949/LM-102911]* Axles w/Large Bearing Bores OD 3.06 in. Req. PN[LM603049/LM603012]