water in oil 318

I have the same issues with my p.u. truck. I have an Edelbrock performer intake, but the leaks come from the front end of the intake. Not enough sealant there. From what I understand if .010 is removed from the head, the intake side of the head or the intake itself needs .0095 removed to keep alignment.
Since aluminum and cast iron expand and contract at different rates, isn't this what is contributing to the leak issues?