Darin Morgan addresses LSA vs cylinder head design in his Induction classes. The wedge head with non-canted inline valves has the worst cross flow during overlap because the air has to make two 90 degree turns to clean the chamber out. Thus a wedge head with headers can benefit from a tight LSA. A true hemi flows straight through during overlap and needs a wider LSA To reduce overlap. A twisted wedge head falls somewhere in between.