Sorry Lorenzo, I should have been more clear. I DO know what the axle ratio is - I don't know how much difference a few tenths in the ratio would make in the acceleration of the '04 vs the '01. But Pontiac says 0.1 seconds faster to 60 mph for the '04 WS6 vs the '04 GTP.

The difference in the intake may or may not make more power - perhaps it added 5-8 hp - but only 500 miles on the clock means you will get better performance in the future - the engine is still tight, 500 miles is the end of the factory-recommended "break in" afterall. His coupe is a bit lighter, but the 'junk' may have evened out the weights a bit. Wait a few months and give him a go again!