Which heads are best

[Wally]

Maybe the squareports do flow better stock, but exept for Remmele (major $$), I don't know any one that makes a decent exhaust for it. No decent exhaust is a waste of big valves and porting work imo.
Also look at the wall thickness of the inlet and exhaust port in the head. Important for strength when your head specialist ports the heads. There are quite a lot of differences there in standard heads as I found out.
Walter