whoops, forgot about chevyvans question.

It seems unlikely that they would cheapen the block castings on an industrial motor, since they work so hard, but I dont have any information on that. As you probably saw from the link, there were many different casting #s for the 366, so it's possible that quality varies. I was wrong about the last year figure, the website lists one casting made until 1988. I stand by my conviction that later fuel injected versions were made into the 90s though.