400M block question

now i know theyre boat anchors but this isnt for me. My uncle got a 400M and at the top of the cylinders theres a little piece missing and it looks like the valves broke it off but he thinks whoever bored it .030 over did it. Has anyone seen this and is the block still usable?

My crystal ball is a little cloudy, can you post a picture?

ill try and get a pic. but its on the very top of the cylinder and it looks like a valve came down and broke it off but it looks too clean to be a break.