The one that sounds best to your ears.
I can sell you a set of turbo mufflers that came from my Summit kit. They are 2-1/2 off set in/center out.
They’ll sound something like the first set of mufflers in the first clip. It’s a 10.5-1, 340 with a 241/247@050 cam w/.548 lift on a 108.
The second video is on a low compression ‘79-318 with a very mild Crane cam on a 112 C line. It was run stone cold for the video in November in NY.
More videos coming soon.
Those are the flat top with two valve reliefs, yes with stock heads.
The KB with the domed piston should be able to be run with a stock head without modification. But the machinist would have to make sure.