[Tcoat]

Originally Posted by yelsew

In my borderline-experienced opinion, I'd say the most likely connection is that when assembling the heads, some sealant made its way into an oil galley, and eventually made its way through the engine like a blood clot on its way to cause a heart attack.

To the OP, I am curious to see what they report from the tear-down, and glad they are taking care of you.

Which is exactly my theory as to why some of the early ones spun the bearings without any work on them.