I just wanted to let everyone know that this IS the best bang for your buck when it comes to buying a mod for your GPX. This kit really woke up the power on my stock GPX. You can feel the difference everywhere. I had some challanges putting the kit together, but that was my lack of mechanical ability. And now that I've put it together...it really is very simple. If I can do it..you can. The kit that I got from Vince at Tbolt came complete with everything I needed. Including the UNI filter, TB rev box, and Y cable. And the price was like $279 shipped. Less than a lot of exhaust systems out there. Just my 2 cents! If you need any help with the install...don't hesitate to ask!