[mreid]

Allen, both bolts were tight. I believe those marks are from when I was mocking up the engine and had a difficult time getting that bolt to thread in properly. I took it apart and that is when I discovered that Quicktime has a problem with their small block engine plate. I needed to grind the starter index hole to match the stock engine plate (this is a well documented problem). After that, it fit perfectly.

After checking everything out, I believe this problem was caused by engine kickback during starting in combination with a cheap cast aluminum starter nose from China.