What is the difference between a casting date on an engine block
and a production stamp?

Also could a block for a 69 camaro be either K 11 8 and/or K 11 9
due to the extended production year?

Depending on what the engine is the cast date and the build date can be as little as a day apart or as much as a few months. The standard production engines are usually close in cast to build date but the more rare engines such as a COPO 427 can be a longer spread. I had a COPO block that was cast in January (9th I think) and a build date of May 12.

I would thinh K 11 9 might be a little too late for a 1969 Camaro.

Thank You Russ..