While adding antifreeze to my newly rebuilt 216 engine for the first time, antifreeze started coming out of hole on the left side just below the manifold. Can anybody tell me what the hole is used for and what should I used to plug the hole that has threads in it.

Thanks

Charlie

1953 5 Window
1994 Harley, Heritage Softail Classic
2006 Chevy Colarado
I didn't say it was your fault, I said I was blaming you.