Help! Anyone have a spare or a fix?

[wzc0014]

Had checked my valve clearances last week and today I had just finished putting my new shims in and putting everything back together. Got 7/8 bolts on the valve cover torqued down properly. Then on this last one, before my torque wrench even clicked I heard a snap and the bolt was spinning free. Now I am really screwed. I don't even know what this piece is called or if it's replaceable. If so does anyone have a spare?