Believe me, if there was any way to work with what he's got, I'd be the first one offering advice. He's fighting a losing battle. The first, and probably only thing to do is go to a much smaller carburetor. The Carter YF designed for a 216 might work, if he can get two of them jetted exactly the same, and synchronized properly. Jon can probably offer more exact advice along that line than I can, since I've been out of the carburetor end of things for several years, teaching computerized fuel injection.
If the manifold cool is using fits a Rochester, it would need adapters, or repositioned studs to bolt the YF on there. The stud spacing is different. He could also benefit from higher compression and a radical camshaft, like Jon mentioned.
I'm about to do some machining on a 235 stovebolt intake to eliminate the single carb mounting flange, and mount a small-venturi Rochester 2-barrel in its place, like the 265 and 283 V-8's used. That would be a much better option than duals from a performance standpoint, but it would lack the "cool" factor of two carbs. It would run a BUNCH better, though!
Jerry
