Ford Racing Steel Differential Carrier for 9" Ford Rear-End Housings.
Ford Racing developed their 9" differential carrier using Finite Element Analysis (FEA) to withstand the extreme demands of NASCAR racing. It is cast from 8620 steel, nearly double the tensile and yield strength and enlongation vs. cast iron. Features bearings caps machined from 4130 steel and ARP bolts. Approximate weight is 21 pounds.