For applications that require a locked differential, this kit includes a MW 35 spline lightweight spool and axles with a larger series 21, 33 spline CV joints. In addition, these center shafts are machined from super strong 300M alloy steel that is shot peened. The outer flange and differential half shafts are machined from 4340 steel. This kit includes the labor of modifiying original wheel hubs for a larger spline. CV shafts and joints are assembled and pre-lubed. Due to the custom nature of this part, please call 1-866-508-6394 or contact us to order.