As far as going true dual, that opens you up to a whole new realm of exhaust options. You now have the choice of running any GT exhaust that you desire. The dual exhaust conversion also helps the car breath a little better so obviously it nets you a couple extra horse power.
As far as mods go, it's a matter of what you are looking for out of the car. Drag, Street, and Road race will all require different types of mods.
For the normal street driver looking for a few horsepower the performance mods that would make you happy are as follows:\
1. Gears
2.Tuner (extra horsepower and also needed to recalibrate the speedo after a gear swap)
3.Cold air intake
4.Throttle body
5.Exhaust (which you have covered)
6.pulleys (yes the do work)
As you add the mods you will notice a great deal of improvement. The best bang for your buck will be gears and the tuner.
after that you can always look into cams and headers. headers are a complete PITA so leave those for last lol
Remember, with performance mods you will need the
suspension to get the power to the ground so springs, shocks/struts, lower control arm, and a nice tire will be neede on your list
the v6 mustang can be pretty quick when done right. check out Central Florida Motorsports when you get a chance. They offer v6 parts and have a '11 v6 running 11's
hope that helps
