If you can alter the rate of opening of the secondary barrels to kick in with the last few degrees of throttle shaft movement, and then more or less dump wide open for increased acceleration when you really need full throttle, the advantages Carb King mentions about having better fuel distribution from the duals will come into play. You would need to make some pretty radical changes in the geometry of the secondary throttle linkage to accomplish that. The flat spot/bogging down problem you're experiencing is a classic example of too much too soon where throttle opening is concerned. A more radical cam will only make that problem more obvious unless you're geared so low the engine is screaming all the time.
Jerry

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