Edelbrock heads on a 340 with KB243 pistons

I've got a 1973 340 + 030 short block that I built with a cast crank, Eagle rods, and Keith Black 243 pistons which are a flat top with valve notches but they extend .018 out of the hole. I picked up a set of closed chamber Edelbrock heads and was wondering what is the minimum piston to head clearance you can run? With an .040 gasket won't that leave me with .022 clearance? Anybody ever run this combo? Do I need to run a thicker gasket?