Wondering if anybody has done any testing between a RB standard port M1, 4150 flange with a 2inch adapter for a 4500 carb vs. RB standard port M1 with the 4500 flange, on say a 440?

Ive got both intakes and gonna try a Dommy. Just wondering what seems to work better.

Also, do the 4500 flange intakes on a 440 seem to like open spacers?

Thanks