360 sb. 2bbl iron intake or 4bbl iron intake with 4bbl to 2bbl flat plate adapter, which flows the best? thank you for your time. RR

Best would be an intake manifold off a 2 hole throttle body fuel injection manifold. I had one on my 89 D250 pickup truck with a 360 in it. You will know it when you see it, it has a Holley throttle body on it with holley cast in big letters on it.