Drivabilty vs. Performance help newbie

Ditto the dual plane. Indeed, the very best 4-barrel manifold for low-end manners is probably the Offenhauser "Dual Port", though mixed reviews. A 750 cfm square-bore carb is not best for low end. A spread-bore Thermoquad or Quadrajet would be better, but good ones are rare. Your cam lift is very high, so poor mixing at low rpm. You can tame a wild cam with Rhoads leak-down lifters, and they give up nothing above 3000 rpm. I got a new small block set for ~$25 on ebay.