hey guys i am thinking about getting my hands on a mach 1000. i curentlly have one in my 03 GT and want to put one in the 91 GT. i know everyone is going to say just get aftermarket but i like the stock look of the mach1000. now i only want to use the headunit, subs, and amps. i dont need to do the speakers because i already replaced them. will this fit? is there anything i should know before i buy this system? i figure as long as the headunit will fit in the dash i will be alright.