Close Chamber or Open Chamber Heads?

I put some open chambered edelbrocks (65cc.) on a basically bottom end 340 (other than rods lightened w ARP bolts, and heavy forged 2316 TRW pistons) rite around 10.2:1 comp, a comp XS282S cam .520/.540 solid, with rpm air gap and a holley 750. 273 adjustable rockers. Made 428HP @ like 5800 RPM. Was going to go closed chambered, but pistons stuck above the deck and at the time I did not want to use a thick head gasket. Looking back I would get closed now (better quench) and run the thicker gaskets.