I have a 2000 ws6 m6 that I've owned for 2 weeks now. (I had a lt1 camaro a few years ago and missed it I sold it to soon.) I have had enough time now to look at the car closer to see what has been done to it and I was trying to get a good idea how much HP it has. It has two cats at the bottom of the stock headers then it goes togather towards the back then splits to duals no muffler no cats, ls1 motorsports lid, the throttle body has been ported and polished no screen. The throttle body seems realy big but that could be me being use to a lt1 Im still looking for a part number or something to see if it was replaced with an aftermarket