For what it's worth
Ok so it's not the C6 or the GTO, but I've had 2 good races with the little Cavalier with it's Ecotec.
I ran a guy with a Scion TC. It was real close from 70 up till I hit the rev limiter at 108-110. It hit's the rev limiter hard enough to throw you forward and lock the seatbelt. It was real close, but if I would crushed him if I hadn't had 500+ lbs of junk that I was moving to California in the thing.
Raced a Focus hatchback with a fart can on it. I crushed him pretty bad. From 75- 100 I opened 10 cars on him.
The Cavalier, even with 500lbs of junk and me running 5-10 over the limit which is 75-85 mph, got 38.7 mpg on the trip. It's an ok trip car.