When it comes time to replace the head gaskets on your 6.4L Powerstroke, make sure you've got all of the necessary gaskets and seals for a complete job, coupled with an ARP head stud kit to ensure you never have to do the job again!Due to their sheer construction and design, ARP Studs do not have a tendency to stretch and loosen, as standard bolts do, keeping the heads firmly in place.