it is a lot for an intake. however, the intake is very restrictive in several spots and getting rid of the restrictions helps increase the horsepower. here is the link to the product with a dyno showing the gains: http://www.needswings.com/ProductDet...?productID=571

of course, you could always make your own similar intake as many members have done with the srt6s on this forum.

if you run a needswings or a similar type of intake, you will just need the cone filter that it comes with (or that you will purchase if you make it). the stock intake has two intake boxes with air filters in them. these stock filters can be replaced with other filters such as BMC Filters, Green Filters, and K&N filters. They allow greater air flow and therefore a slight increase in horsepower and throttle response. However, the gains by just adding filters are nothing compared to getting the Needswings, making your own, or doing an SL55 setup.