Leaking from this hole, anyone know what I'm looking at?

[clytle374]

Thanks for any help.  Haven't been on here in forever, but my sister's GM90 overheated and I'm 100 miles away from her now. It is dumping water from the head from a hole just under the injector.  Not sure if this was a freeze plug, it wasn't frozen for sure.  I just can't remember what this hole was. 

I built this long ago and it got them through most of the hurricane flooding. 

[broncodriver99]

Definitely looks like a well for a freeze plug.