Originally Posted by vinniekq2
in the carbs venturi or in the intake runner?
Well, velocity in the runner can impact volume so it becomes important only because of its effect on volume and condition. If the heads can effectively maintain a high quality of intake charge and fill the cylinder then the velocity can be lowered and you will make more power (hence larger ports are used when going after racing power numbers).
velocity in the carb can have a significant impact on "condition" depending on how well the carb can atomize and disperse the fuel- as the quality of the carb goes up the need for high velocity goes down, you can then run larger venturi and have more volume for a given pressure differential across the top and bottom of the carb. Hence a good carb will have lower velocity with better condition and more volume.
velocity is only one way of many to affect volume and condition (which is what you're really concerned with).