Newbie 318 piston question

Back in the 80's and 90's the piston choices for a 318 were either stock replacement pattern flat-tops or 11:1 domed pistons. If you were running large port open chamber heads you needed the dome or you had to mill the heads quite a bit to get reasonable compression. A domed piston in a large open chamber isn't as efficient as a flat top with quench, but a lot of engines went together that way and ran fine. Valve clearance can be an issue with domed pistons.