PatriYacht

I've been running heads like that for 6 years now. Mine were intentionally ported that way. It wouldn't surprise me if yours were ported and that one broke through. It would take a lot of corrosion in an area that is normally dry to do that.

Rookie

iTrader: (4)

I see that at JimV's shop when he is porting heads. If the cores shift during casting it can change the thickness of the wall stock. As previously mentioned you can sleeve it if you are worried. I can get you pics of heads that have been in service for years like that without any issues. I don't believe he sold you bad heads.