I raced a gt back when I was stock. From 0-60 it's a close race. if you drive right I think you might be able to keep a bumper ahead of him until 60. If it goes much past 60 he'll get you.
From a roll, forget about it. He'll beat you.
With my current setup (up-pipe, down-pipe, mid-pipe, and UTEC) I raced a stage 1 roush 'stang. For all intents and purposes it's pretty much just a stock GT. I beat him pretty good both from a 10 MPH roll and from a light.