Coming from an '06 LS2 with Kooks LTs and full exhaust, ported intake, cai, and a bunch of suspension mods on DRs, I consistently ran 12.40 @112. Biggest problem with the Goat is not the weight, but the massive wheel hop. It is one of the hardest cars made to run a quarter with consistent times.
As for ur question... Unless he has a bunch of seat time at the track with that car, u have the edge, even cammed imo.
As mentioned, the GTO is one of the best daily drivers out there. Good at many things, just not great at any! Sure miss mine.
Had a couple friends with TT or Supercharged with over 750rwhp, without susp help, and I out ran them on the track often.
Good luck!
Troy
I will say, my new GT will woop on my Old GTO!