[docrodg]

That dear sir is a broken head stud (cue crowd screaming in fear). Looks like you will be tearing that engine down. If you are lucky your case will already be reinforced with case savers or be the stronger aluminum case. If that is the case (pun intended) then a top end rebuild will likely do. Test the stud if curious... if a magnet sticks to it then it is a steel stud and something went seriously wrong to break it. If non-magnetic it is a Dilivar stud and you will want to replace all the dilivar studs with steel, ARP, or Raceware studs before they too snap.

Chances are it is dilivar. How many miles and what year/engine? That info can give you an idea if you should do a full rebuild. Also check other wear items like valve guides. If run for a while like that you may have damaged a cylinder and head as well.