closed chamber vs open chamber edelbrock heads

possible? Sure. Pratical? Sure. need a thicker head gasket, and a little measuring to get the right thickness. The piostons you have are flat tops, the ones with 2 valve reliefs, right? You'll need to make sure the piston that comes out the furthest has enoughr oom to do it's thing inside the heads' chamber. Just be careful, take your time, and it's fine.