GM Chevy 8.5" 10-Bolt Rearend Posi Unit - 28 Spline * New GM 8.5" Posi Unit - 28 Spline * Eaton-Style (clutch) Posi Unit * Fits 2.73 & Numerically Higher Gear Ratios * Nodular Iron Casing * Heavy Duty Composite Clutches & Forged 4130 Internals