I pulled the intake off and didn't see anything on the top side of the valves nor any scratching or scoring.
I decided to drain the oil and to my surprise at least 1 gallon of straight green anti-freeze came out, no milky oil at all. I dumped the anti-freeze and went to drain it again then the oil, milky came out.
Last oil change was 1K miles ago.
At this point, I'm thinking a cracked block or somehow punched a hole in the aluminum heads? These are Speed Master 3V heads for reference.
Engine is coming out but curious of the root cause of the failure.
Thanks,
John