Here's what the write up says - Why don't you sell pod/cone/pancake filters?
Don't use a cone filter. There's a reason i don't sell them to people. I don't offer anything that's sub par or not good for your bike. No matter how you tune the bike with a cone filter, you will always have either sub par performance or an issue with one or more throttle stages. The VT600 has a vacuum operated CV carburetor, which means that the slide is operated by the vacuum in the venturi of the carburetor.
For the slide to operate properly the venturi requires a steady negative vacuum, a pod/cone/pancake filter creates a large amount of turbulence right next to the slide, destroying the carbs ability to properly deliver the right amount of metered portions of fuel and air to the motor. On a flow meter bench test, pod filters created a stupid amount of turbulence in the carburetor, whereas a velocity stack succeeded in reducing the turbulence in the venturi making tuning easier and allowing the motor to perform better. The stock intake system is actually designed around a velocity stack principle; both dual and single carb models because the engineers know this is an effective way of delivering air to a CV carb. Now it bears mentioning that A mechanical carb where the slide is operated by a cable attached to the throttle, a pod filter is less of an issue. Granted, on a mechanical carb a velocity stack does improve performance, but a pod/cone filter will work. The CV carbs on the Honda Shadow line are well made, easy to use and easy to upkeep, requiring minimal knowledge and skill to maintain and upgrade them. If you want to increase your bikes performance and get rid of the fugly stock intake, Pick up a velocity stack/s and a performance jet kit from the site, READ the entire FAQ page and watch my youtube channel tjbrutalcustoms ;) Everything you need is there to get your bike running and tuned properly!
I suggest my velocity stacks, not because I'm trying to turn a buck but because Its genuinely the best means of increasing performance on your bike before going to a jet engine. messing with your mains and pilots wont help your situation honestly.
If you pick up my Velocity stacks with my performance tuning kit you will have most everything you need to get set up. You may want the vacuum plugs too. I suggest watching my youtube videos as well as they walk you through the whole process.
No idea what that calculator is but its WAY off! LOL