I agree, 30 cc pump should be fine (at least in my experience). You want as little accel pump as you can get away with. White cam, position 1 and a .028" squirter should be enough for a 4 spd. About a 64 main jet should be about right.
I've adjusted the idle mixture on the secondary carbs to get a good idle. These are necessary to get a good idle because the secondary butterflies are cracked ever so slightly so they don't stick in the bores. A good basic adjustment is to remove the carbs and back off the idle stop screw to seat the butterflies, then run it up until the lever just keeps the shaft from sticking. You should have about the same amount of light showing in each barrel, and if not, then loosen the butterfly screws to allow them to float in the bores and tap with the screw driver handle until they seat tight. Tighten shaft screws and repeat adjustment. You can pull plug wires out of the cap while it's idling to check mixture strength for each cylinder - very effective. Pull out of the cap so you are not holding a live wire looking for ground!
I'm starting to wonder if you have a timing curve issue. Do you have a vacuum advance hooked up? is it connected to the ported port on the carb or manifold vacuum? You said you have a 70 engine. Are you running the dual diaphragm advance? Make sure you are getting a smooth advance curve as the RPM increases.