Not Fast, just "Less Slow"
I have the super six 2bbl carb and manifold, but looking at it compared to my 1bbl, I'm kind of underwhelmed. Man, those are some tiny throats. Looking at total cross-sectional area, it's not an enormous improvement, and the orientation is 90 degrees away from what you'd want. It makes me think dual 1bbls would be much more effective. Actually, I am visualizing a pair of SU HS6's, like a Jaguar -- the motor's the same displacement, and they are as simple as carbs can be.