You'd likely die terribly on a road course. That IRS, braking and suspension would bury you.
what gearing do you have, what tires and wheel size? Let us say 360 rwhp is the average for an 03 Cobra and most folks were putting 12.9s or so with the completly stock mix. Where are you in the 1/4 mile?
from a roll...you'll get annhilated by atleast 4 lengths, on a road course, annhilated by miles, at a drag strip, if you can both drive, it'll be close but he'll prolly win
You can actually hang with in a drag race if not beat a stock 03 cobra. You have a tremendous weight advantage. It is not unheard of for an LS1 car to put down number like yours and I got beat when I was stock by a slightly modded one. You have a weight advantage over an LS1 too. Try it and see.