It's likely that something either happened to this body and it was pulled off the line (or something), or perhaps there was some lag with LS-6 blocks and they all had this issue.
Never happened. Once a body was started, it was built to completion. There's absolutely no room in an assembly plant to set aside a body for a while and it would cause ripple effects throughout the assembly process.
I've never seen a list like that for Pontiac, but I may be in a position soon to see if I can locate such an item.
