Make no mistake, dual plane manifolds are a crutch. In an ideal world all performance carbureted manifolds would be single plane. But the problem is many carbs out there do not provide adequate atomization with the lower vacuum signal of the single plane. Also, if the cylinder heads feature intake ports with too low velocity for the intended application the problem worsens. But where carb atomization is adequate and intake port velocity is high, single planes will always be the better choice in performance applications. But if you plan to keep your current carb and it proves itself to be inadequate, in terms of atomization, then yes a good high rise dual plane may be in order.
Also, this being a completely new combination, your problems are likely stacked. My approach would be to make one change at a time. For example, your new engine my need higher shift points now to take advantage of the power increase in the upper rpm range, so that's great start. Also, your stall speed may be too low for the cam.
Please keep us posted on the results as you experiment.