Stock mercury bolts are 70000 and are one use only , AKA throw away after one use !!Will fit ALL 3.0 -3.2 optimax( 225-250-300 opti) as well as all Mercury 3.0 EFI perfectly (225-250-300 efi ) , Early EFi uses two longer studs per head , notify if you need the longer studs for upper two bolts per head You receive 40 grade 10.9 ( 150000 psi ) studs as well as 40 flange nuts call or text with questions or concerns
119.00 shipped lower 48 609-315 two six four zero