hi i have a pretty much stock 89 gt conv. and was wondering if any body can tell me what is the first thing i should do to start to modify my car so i can start to be part of the muscle mustang group plus kind on a budget right now  but wont be soon just want to get started now so i can put a little more umph in my stang i just bought this car and its runs pretty good and looks  nice but it has flow masters on it  but doesnt sound like other stangs with that deep nice noise please help  

Set initial timing to 13-14 degrees, change engine, trans and rear end fluids to synthetic, K&N, reset the TPS voltage to .995-.998 volt, and a set of 3:73 or if it's an automatic 4:10 gears.  After that you'll have to start spending money although the gears cost $150 and about the same for installation.