can anyone identify this 10 bolt posi rearend

i need some help identifing this 10 Bolt posi rear end. it has 2.41 gear ratio,coil springs,disc brakes,and looks like a factory sway bar on the lower arms.the numbers stamped on the axel tube is WN P 026 N and just below that is stamped BO63. from inside of backing plate to backing plate measures 56 inches. thanks,wc