1998 4wd Blazer. Someone replaced the head gasket before I bought it.

1) When changing the passenger side valve cover I noticed the ground wire from Body to engine was not connected (on the engine side). Any idea where this bolts in?
2) Again, while changing passenger side valve cover and feeling for oil to pinpoint a oil leak, I noticed a hole in the engine. I cannot see it as its in the back of the engine facing the firewall, just under where the valve cover meets flush. It about 3/8" in diameter. ANY CHANCE this is where the ground wire bolts in????

 

Mine was connected to the back of the passenger cylinder head

 

Mine is connected to my front part of the frame.I also have 2 of them that bolted to back of the engine head.

 

When it comes down to it you could attach that ground wire in a variety of places. You could either take that wire and connect it to anywhere on the engine from the negative terminal or run a new wire from the engine to the negative terminal. Anywhere on the engine such as the alternator bracket bolt in the front of the alternator when you first raise the hood is fine.