Hey I called the local exhaust shop and the only "custom" exhaust they do is the Vortex Cherrybomb si/do exhaust. I said that I wanted it loud and they said that they were now "new and improved", and louder. Now I have instaled this kit before on my friend's truck, now it was pretty loud, but not 40 series yet. Oh and he said $220, so any of you know about this "new and improved" Vortex, or any one know of a place online to get them. Thanks guys.