I don't have any real numbers to compare but I do have the cars. I have a stock '04 GTO (SLP skid plate and skip shift eliminator) so no performance adders and a '02 Firehawk. The Firehawk has bolt on sub-frame connectors, Pro 5.0 shifter, SLP Y-pipe, skip shift eliminator and it is a later '02 with the SLP high flow lid and air filter so it is rated at 345 HP. I have never had either car at the drag strip, truthfully the Firehawk has the 1LE suspension package on it, so hooking up would probably be a problem. But I have autocrossed both and they is no comparison. The Hawk obviously handles better, but also has more power. On the street it's the same thing. The Hawk feels light, fast, and rev's really quick. The GTO is fast and powerful, but it seems like it needs a little more. I'm sure with the LS2 the GTO's are very even. This summer I hope to put the two cars against each other and see which one wins. The weight difference is about a 100 pounds more for the GTO and I remember owners of the '02's reporting about 315 RWHP for manuals and 295 RWHP for autos.
BTW, the 2001 and 2002 FH's and SS's were the quickest stock. They came with the LS1 motor and LS6 intake manifold. The 2002's made in late July 2001 and after also received a 'factory' high-flow air lid and filter. Owners of earlier '02 cars were able to order the lid and filter and add it themselves. But a simple after market lid and filter which most people did anyway would yield similar results.