USA Standard ring and pinion sets are the right choice to add confidence to your install. USA Standard Gear offers a full line of ring and pinion sets for a variety of common and hard to find applications. Fits 1985-1992 Ford 10.25 inch 10.25 Inch Ring Gear Diameter 31 Spline Pinion Fits 2008-2010 Ford 10.5 inch housing with OEM ring and pinion set 12 ring gear bolts 3.55 ratio 1 year warranty against Manufacturer defects Technical Notes: This gear set is designed for 92 and down housings Features and Benefits: Fits 1985 - 1992 Ford 10.25 Inch 10.25 Inch ring gear diameter 31 spline pinion Fits 2008-2010 Ford 10.5 Inch housing with OEM ring and pinion set 12 ring gear bolts 3.55 ratio Details: AAP_UDA_4: 65 Fitment Notes: 10.25 inch. 10.5 inch. 1.26 inch. Long Spline 12 Bolt Cover 3.55 Ratio Ring and Pinion Application Summary: 1985-1998 Ford E-250 Econoline (Rear) (Note: 10.25 inch. 10.5 inch. 1.26 inch. Long Spline 12 Bolt Cover 3.55 Ratio Ring and Pinion) 1985-1998 Ford E-350 Econoline (Rear) (Note: 10.25 inch. 10.5 inch. 1.26 inch. Long Spline 12 Bolt Cover 3.55 Ratio Ring and Pinion) 2000-2004 Ford F-150 (Rear) (Note: 10.25 inch. 10.5 inch. 1.26 inch. Long Spline 12 Bolt Cover 3.55 Ratio Ring and Pinion) 1985-1998 Ford F-250 (Rear) (Note: 10.25 inch. 10.5 inch. 1.26 inch. Long Spline 12 Bolt Cover 3.55 Ratio Ring and Pinion) 1999 Ford F-250 Super Duty (Rear) (Note: 10.25 inch. 10.5 inch. 1.26 inch. Long Spline 12 Bolt Cover 3.55 Ratio Ring and Pinion) 1985-1997 Ford F-350 (Rear) (Note: 10.25 inch. 10.5 inch. 1.26 inch. Long Spline 12 Bolt Cover 3.55 Ratio Ring and Pinion) 1999 Ford F-350 Super Duty (Rear) (Drive: 4WD, RWD / Note: 10.25 inch. 10.5 inch. 1.26 inch. Long Spline 12 Bolt Cover 3.55 Ratio Ring and Pinion)