Features precision-rolled threads for optimum engagement, to prevent galling and promote more consistent torque loading Wide underhead flange design provides even load distribution for optimum sealing of surfaces - preventing leaks Tensile strength rated @ 170,000 psi; superior and stronger than OEM and stronger than grade 8 fasteners External primary fastener kit (includes primary cover, clutch cover and 1/4" stainless steel washers) Manufactured by ARP« to Feuling's« exact specifications Includes moly assembly lubricant for installation Quality 12-point heat-treated stainless steel Made in the U.S.A.. BOLT KIT PRIMARY XL 91-03