I'm going to purchase a centri system and cannot decide between the vortech v3-si kit and the procharger p1sc-1 kit. I like the fact the procharger has a dedicated drive, but that also worries me with another pulley being added to the end of the crankshaft putting extra stress on it. I have seen dyno numbers from 575 to 700 with either kit. I've personally had a procharger before on an 04 gt and was pleased.