I would have thought that engines produced in the late 60's that were subject to a "core shift" would have been disposed of long ago by attrition or warrantee claims. I'm finding that some of these may have survived.

Has anyone experienced Core Shift in an engine block (383, 440, etc.) that did not become a problem until years later when the block received its first 30 overbore? By problem I mean overheating or cracked cylinder wall.