TOPIC:

take that little scope and stick it down in there first to make sure its not a screw that got dropped down in there while valve cover was off,that tends to happen over a period of 30 years.if it is off the guide,you know what to do next!

The issue for me isn't if I pull the head, but rather when. I'm supposed to meet people about 200 miles from here at 10:30 tomorrow morning. Do I pull the head tonight and see if I can get it sorted out quickly, or try my luck . . . . or do I just cancel?

What do you think my best case, worst case, and most likely case scenarios are?

buy yourself a head gasket,valve cover gasket and exhuast crush gaskets.look down through head with scope to see if the screw is actually missing,if it is start wrenching fast!if you were close id come help ya.

You should also drop the oil pan to see what else is laying down there. If it is #11 then the chances of that falling out straight to the drain plug while the engine is whirling around are pretty slim.