there's a few slight difference... wheels, suspension, sway bar, hood. otherwise it's basically the same car. I have no idea what the governor is at.. but I got my car past the speedometer limit of 155.. and I had plenty rpm's left.. based on how long I pushed it past 155 and where the rpms were, I think i hit about 162... and then I let off. and I will never again be testing my car like that... so... 162 ain't bad. my cuz said he got his C5 to a little over 180... which seems about right. the z06 claims 200mph.. I think it could do more.