Rear End Bolt KitFord 9 carrier bearing stud kit, 3.250 Under Head Length, 1/2-13, 1/2-20 Thread Size, ARP Carrier Fasteners 250-3004Use ARP Carrier Fasteners and Bolts When assembling a rear end, optimum reliability can be obtained by employing these rugged chrome moly bolts and studs. ARP's carrier fasteners are made of 8740 alloy, heat-treated to a nominal tensile strength rating of 200,000 psi, and black oxide finished.