As far as the throttle response goes, etween a small venturi and a large venturi carb, the larger venturi set up on an engine with the correct power range for that size carb and calibrated properly, will deliver good throttle response. So if the carb is too big for the power range of the engine, then generally a smaller venturi carb that is suited for the power range will deliver better throttle response, and quite often allow the car to be faster.