I'm trying to reattach my head after replacing the gasket. One of the bolts (#8 head bolt hole) is getting "stuck" when I try to tighten it. The threads on the bolt aren't stripped - is there some sort of tool I can put in the hole to clean it up? What would cause this?? When I took the bolt out, I didn't have any problems.

Oh yeah, this is a B18C5 head going on a B18B block.