you guys really need to do some research and get your facts straight
http://www.insideline.com/chevrolet/...full-test.html
look at the article the 603 hp is at the crank that is also with a corsa catback... or atleast all the other numbers in the article are so i would guess it the same. do some quick math with a 15% drive train loss and 603hp x 0.85=512.55whp
also read the thread i have the L99 exhaust on my car which just by looking at the differences you can see is more restrictive meaning i easily would have hit the 500whp mark if i had the LS3 exhaust.
Third the the car in CO had a full exhaust on it. Mine is still stock which would I'm guessing is good for another 50-60whp if not more on a boosted car. Well find out soon as mine is going on today with any luck
The biggest thing you guys need to remember is its not all about the numbers on the dyno. Ask any experienced tuner or any tuner at all and they will tell you every dyno will read different especially between the different brands. Quick example: when i had my cobalt reading the threads with the mods i had some people were posting up 250-260whp. I dynoed at 225whp on with the same mods. I figured something was wrong and took it to another shop just to make sure and guess what i all of a sudden made 255whp just by putting it on a new dyno.