Maximum head milling?

I'm interested in building for quench. Of course, this is quite difficult with an open chamber head, but since the chamber sits about .200" into the head, if it could be milled that much, and the right shaped and CH piston found, it can be acheived. I've read that some have angle milled the head that much, favoring the post side, which partially closes the chamber. I'm thinking of going that way. It then becomes a matter of finding the right piston (possibly the KB 268 which has a dish).