Engine milling maths

If you mill one side of the head, I'd always mill the corresponding amount from the intake side. That way you can use the heads on any block. If you are just cleaning up or equalizing the block decks, I doubt you would have to take that into account. If you are milling .060 from the decks, then I'd be into milling the intake. But typically I'd be looking at different pistons, even custom. But if we are honest, there are usually at least 6 different ways to do anything. As for volume, I would assume the formula would be different. Maybe contact Edelbrock?