For 9" & 9-1/2" Ford standard 28 spline pinion street or pro gears, nodular iron housing for 3/8" fasteners, angular contact steel ball rear bearing and Timken® tapered front bearing. All pinion supports come pre-assembled. The bearing pre-load is set through the use of a solid hardened pre-load spacer rather than a crush sleeve or stack of thin shims. The spacer is factory machined to the requeired preload for each assembly. Pinion seals are included. Stock Ford yokes must be shortened for proper pinion nut thread engagement. Installation - Service Instructions can be found on Service Bulletin #0051