ANTIFREEZE OUT VALVE COVER BOLT-HOLE?!?!?!?!?!?!?!
thats not uncommon, usualy it the end exhaust port holes that that happens to (thats why the factory uses studs at the front and rear exhaust port holes) the valve cover bolt is odd, but i wouldnt morry about it. just buy some studs and stud he holes (much better than the bolts anyways) they did lighten alot of the castings on the 73 and newer engines, so thats probrably what happened ,they just broke into the water jacket. i wouldint worry one bit..........