PRP Velocity Lessons

few years ago,i went to a flow seminar put on by superflow, harold bettes , vp of super flow conducted the 8 hour class. it was very informative class. he stated, that engine doesn't pull 28 " of vac, if it does, you are loosing power,, my bench is calibrated at 25 :, he also stated, that 20 : would be more accurate. carbs are tested at 20". his last comment was, port shape and port velocity are everything, don't get hung up on flow numbers, port velocity is what fills the cylinders, creates higher cylinder pressures, = more torque, = more power, just food for thought.