just data fellas, it's all just data....pick what you like to run with...I like the design of Rob's, hell, I even like Rob...but, it's your money, he's just giving you the data....doesn't mean you can't run what you have now...but, there are a lot of claims out there, but, look who's running the times at the track. If you aren't into to drag racing and just looking for performance, you could get by with less...I like the looks, and was very skeptical about moving from the single to the dual, but having just romped on mine with the single, having Rob install the dual in the parking lot of the hotel, and taking her right back out again....well, it was instant throttle, instant accelleration, and this "sucking" sound that only a man can dream about, coming from the front of my car....I was convinced...with that said, I hate engine covers with a passion...so, even if the air boxes flowed better, I would still run the tubes....just me...