Damn,
I have duty next Saturday, or I would bring out my Supercharged Z06. Having had a VERY modified GN and now the Z06, I would be careful. Yes, with a few mods, and GOOD tuning you should have no problem against a stock Z06, as traction will be your brothers biggest problem. Just some observations from my GN and the Z06 (which is supercharged, so I can't really compare stock. Mine was stock for 5 days after I got it.), but the Z06 would kill the GN from 0-60. The GN would catch up REAL quick from 60-120, and I think the Z06 would easily walk away above 120. I did get the Z06 down the track for one pass about a month ago. It was pretty much useless. I fishtailed all the way through 1st, 2nd, 3rd, and a little in 4th. I ended up running 14.7@116mph.
Please don't get me wrong, I miss my GN EVERY day now. But, be careful before taking on some of today's "fast" cars. I would say your GN would need AT LEAST fuel, better turbo, probably exhaust/downpipe, GREAT tuning, traction, and of course more boost & octane (or alky) to have a good chance.
Hope you guys enjoy yourself Saturday. I will run my car again here in a few weeks probably. I still need to learn how to keep the traction and improve my 14.7 sec. pass (Geez, I didn't even need a helmet for that.)
Derrick