Steel Spool For GM 12 Bolt Car With 30 Spline Axles 4.10 And Up Yukon Gear & AxleYukon performance spools are made from the highest quality materials to ensure high strength and long life in performance applications. Details: Fits GM 12 bolt passenger car with 30 spline axles 4. 10 and up ratio only Provides 100 percent traction to both wheels at all times Not recommended for street driven vehicles Machined from high quality steel alloy Limited Lifetime Warranty Against Manufacturer Defects Sold As Each Fits Vehicles: Buick