In finding where my water leak was coming from, I put a borescope back behind the intake. I found on the passenger side, where the intake mates to the block, there is an extra passage. It looks like it goes down into the block as an extra coolant passage, but for some reason it does not connect to the intake, despite there being a gasket on it. This is a 2000 6.8- any idea what it was at one time? I'm guessing Ford designed the block differently than what went into production or something.

-Michael

 

A couple times per year we get this question.

Its normal. It's a hole to nowhere. We all have it.

 

If you put that head on the other bank, then it will be used under the thermostat. Heads are interchangable side to side.