Sorry, by manifold I meant anything on the output side of the blower, under the carb hat, inside the carb, etc. The pressurized side of things.
Since the carb vents are under the carb hat the float bowls are subject to the same pressure. As the butterflies open they pull the fuel into the engine, you just need to ensure the fuel pressure is greater than the air pressure to keep the bowls full of go juice.