Coolant was getting into the cylinder in the example posted. If the hood is still present and even if not. Could you not have a look at that engines cylinders? That the used head came from?

It would not be conclusive if a cylinder was not washed down. Actually steam cleaned. At the same time if one appeared to be. You then have a solid indication of not to risk using the head.

When I mentioned can act like a one way valve. Molecular size and charactaristics of elements and materials do enter into the picture at times as well. You probably remember when synthetic oil was introduced. People were screaming about their engines leaking out. Besides any solvent type action. The base of synthetic oil was probably involved in another way. In any event the synthetic base was modified and the problem drastically reduced. You seldom hear of it anymore.

A mans repair approaches to things are his own business. No matter how sorrid or counterproductive they may be or may not be. They are his. In this case sure it may work out. Or may not. Your gamble.

I understand this. There is only one sure thing. The odds do not favor this approach. Still you could luck out and say I told you so. Personally I would like to see it work out than not. Say it even did. Would you be thinking of the cracks all the time and always waiting for something. They are not going to self heal up.