AL3Z4026A, 19588-010, YDGF8.8-31-1 ** Fits Ford 8.8" All Ratios (Ford 8.8" IRS SUV, Ford 8.8" - 31 Spline, Ford 8.8" IRS Passenger Car 31 Spline,Ford 8.8" Reverse Front 31 spline, Ford 8.8" 2010-2014 Mustang & Straight Axles w/ 3.250" OD Pinion Brg. 31 spline, Ford 8.8", '09-'14 F150 only - 31 spline) -31 spline -4-spring, clutch style positraction -Internal gears are manufactured using forged 4320 steel and cut to provide stronger teeth -Fully rebuildable -Assembled in the USA Technical Notes: DTA recommends the use of high grade GL-5 gear oil and Limited Slip Differential additive for long life and smooth operation. Part number OILADD or 43161. The use of synthetic oil is allowed but may result in aggressive or noisy operation. This unit requires use of carrier bearing & race set number A36 (TIMKEN BRAND) which are included.