i've used the kb quench dome pistons (kb184) a couple of times with non-quench iron heads. in my opinion they are the best solution for a pump gas iron head engine. kb is making forged step head pistons now. if you don't want to use that type of piston a flat top (many availiable) with quench heads are availiable. indy and edelbrock make large runner volume heads if thats what you want. i suppose it depends on how much power you want but 550hp is fairly easy to get on 210-220cc intake ports. do a little research; there's a bunch of stuff out there.