Okay, so you blew a head gasket on your 6.4 Powerstroke; honestly, its not that uncommon especially if you've racked up some miles or have aggressive tuning delivering higher than stock boost. But don't worry, it can be fixed! Replace your blown or leaking head gaskets with these quality MAHLE gaskets. And while you're in there, in order to prevent this from happening again (honestly, replacing head gaskets isn't that much fun), don't forget to replace the factory head bolts with a set of ARP head studs. These gaskets are sold individually, so if you need a complete set for your engine, make sure to order two.