Yukon steel spool for GM 12 bolt car with 30 spline axles, 4.10 & up. Yukon Performance 2-1/16" deck steel spool for GM 12P with 30 spline axles. Spool uses 1.785" journal bearings. fits 4.10 and up. Yukon performance spools are made from the highest quality materials to ensure high strength and long life in performance applications. Spools provide 100% power to both tires at all times and are a lower cost alternative to lockers. Spools are not recommended for street driven vehicles. Yukon Performance spools come with a one year warranty against manufacturing defects. This spool requires the use of a C-Clip eliminator kit to be used.