Check the listing for details. Rear Axle Kit Fits Ford 8.8" Diff 31 Spline 31-1/16" Long. Condition: New. Listed at 63.96 USD. Rear Axle Kit Fits Ford 8.8" Diff 31 Spline 31-1/16" Long SKU: ZA K630207 Brand: USA Standard Gear Condition: NEW MPN: ZA K630207 Manufacturer: USA Standard Gear Manufacturer Warranty: 1 Rear Axle Kit Fits Ford 8.8" Diff 31 Spline 31-1/16" Long, 630207-. USA Standard Gear uses advanced alloys and the latest heat-treating technologies to produce a strong, durable axle. This kit contains all the components to replace, repair, or upgrade axle shafts so your vehicle will be up and running fast.. USA Standard Gear replacement axles are built to meet or exceed OE quality. Engineered for an exact fit, USA Standard Gear axles are easy to install. They are heat treated to enhance strength and provide years of dependable service. This kit contains all the components to replace, repair, or upgrade axle shafts so your vehicle will be up and running fast.