You should of did some more research and not just take vendors word for it..
http://www.grandprixforums.net/threa...Explained-here
http://www.grandprixforums.net/threa...ding-Your-3800!
Read read read read read
Even stock cars knock even with the stock 3.8 pulley and some still chip pistons. The lower the pulley the more deadly KR is. You shouldn't touch the pulley until you have some way of scanning..