If you are going to run the open chamber head, then it needs to come out of the deck. If that means doing that will make the compression too high then use a dished piston.
Lets say the depth of the chamber is .060 although most are .100 unless they’ve been milled. And you run a zero deck. That’s .100 clearance PLUS the gasket. Even if you had an .017 gasket, which I think Cometic makes, you are still at zero effective quench.
I’m not a big quench guy, because all that started with GM heads having a garbage plug location. But, I don’t think being .100 away from the head is anywhere near ideal either.
That means using the numbers above, you’d stick the piston out of the deck .060 and use an .039 gasket. That’s .039 away from the head. Set your compression ratio with the size of the dish or maybe even a flat top depending on chamber size and stroke.
