I'm not trying to torpedo your post, but I just now looked at your "216 Head Removal" posting.
I hope Jerry (Hot Rod Lincoln) or one of the other more experienced guys reads this.
First thought I have, has this engine been running too lean?
Your description said, "No smoke, no overheating, no coolant loss, no milky oil".
It looks to me that the head gasket burned (material vaporized, see previous posting picture) from overheat.
You also mention, "duel zenith carbs". Interesting. I wonder if they are sized/adjusted correctly.
Maybe this is something to look at before you swap parts over to a 235.
