Probably not, you are going to have to do more than that. I dont think the stereos hurting too much though. But even without it your still not making that time.How much would it take to get a 1988 mustang gt into the 13's? With 125 pounds worth of stereo in it. Would 3.73's and a full exhaust do a high 13 trick?
2007 GT... ofcourse its going to feel slow after driving that thing around.