has the Saleen Supercharger 575 FWHP- 9.5PSI and a safe tune from JDM Engineeing in NJ. They say under 500rwhp is ok, I'am at about 475rwhp, enough to scare the shit out of most people.
Suggestions for more seat of the pant's HP ( 1)- you probably have 327rear diff gears, go to 373s it will be like adding 75HP.(2)- underdrive pulleys+10-12 rwhp. (3)- Alum Driveshaft +10-15 rwhp. I went from the stock 355s to410s before the Supercharger, it was like adding 100HP.
Two Ebay listings in New York state for 2011 Mustang GT's # 200991016216 and # 291041068295 check them out. They are at Ford Dealers, you could get them for less on a clean deal with no trade in, and a warranty.
Take the money you get and put it down on a 2011 Mustang GT, 5.0- 412 HP stock, there are many of them out there for sale. $20,000 some less, most more. Things happen for a reason! You wanted a New Mustang anyway. Good Luck!
I couldn't find a supercharger for your v6 when I looked for one, you may have to go to the v8, like the 03 Mach 1 stock rated 305hp but more like 330. The 03 GT is about 260hp.