In the OP's example"440-3 at the end of the casting number", the dash number is called the Core Casting Index Number. This is not a "revision" but merely a number that denotes the number of core components that were changed in the casting core used to make the sand mold. The abrasive nature of sand wears out the components and, rather than scrap the whole core, they replaced individual components. The highest number I have ever heard reported was a -13.

The fact that the -3 is consistent with an engine series is merely coincidental.