That’s all good but yes, you're missing my point. Which is:
1. I remove studs.
2. I do not remove manifold.
3. I replace studs.
It seems that this was your situation as well.
In his write-up, (which was very helpful), his situation was.
1. Could not remove studs.
2. Removed manifold.
3. Replaced studs.
4. Replaced manifold.
I really can’t put it more plainly. In fact, Maine briefly mentions my(and your) situation in the very writeup portions that you posted here. He omits whether or not the coolant needs to be drained for this situation. This is the basis of my question. Since I was unable to find any information on the internal construction of the manifold, I was concerned that the studs provided some kind or isolation between the coolant and the header.
It turns out that I was justified in my concern, because, due to design or corrosion, the removal of the stud will cause the coolant to drain out. This happened to me. Moreover, I had already drained the manifold and there was just a small amount in the bottom of the header.
I think you miss my meaning and why I post this at all. My leaky stud hole is problematic for a number of potential reasons.
1. Pretty bad. The stud through-hole is not isolated from coolant, and the presence of coolant in this area means that there is only an exhaust gasket separating the coolant from the nice-water-free inside of my engine cylinders. That gasket is newly-loosened what with not having a stud there anymore. If I had coolant in my bore, that would be pretty bad.
2. Not so bad. Sometimes in engines, studs will terminated in a passage, in this case I guess that the stud could terminate in a cooling passage, and my leaky stud would just have been coolant from the engine. I think this is unlikely, but if true, just a matter of spilled coolant.
3. Just me. Maybe my manifold is just rusted through somewhere?
I think in any of these cases, I think it is worth informing the interested that they should definitely drain coolant before attempting this job.
All that stuff above... was why I said the thing about turning over with the decom open...