I resemble that remark lol....

 

Well..., I have a leak on 6. I am sure it is not the HG since it started before the HG job and is still remaining.

Is a crack the only cause at this time??

 

You have a crack maybe.
Sorry.
That is not nice to hear after all that work.

The only other idea is that coolant is coming in the intake runner for #6 from the intake manifold.

The #8 runner would be closest to the coolant? Yes? or No..
I don't think the intake manifold has coolant running next to the #6 intake runner.

Coolant could be spraying up from the liner..

Look in this video.

You can see #4 leaking from where the liner would meet the
head gasket.

 

you can preasure test it while using the bore scope, but it sound like you may have a slipped linner.