I am not sure about a swirl effect, but I have heard that the stock carb requires a certain amount of pressure to operate correctly and that in certain areas people were haiving problems with the clamp on k/n because you do not have the pressure.
jsyi, let me know how the edelbrock worksout with the clamp on, I plan on using that set-up as soon as they get done with your bike so I can get my carb. You will have the very first production unit, so were all counting on you for some feedback. lol