I guess considering I have a forced induction v6 (turbo) i would be a good person to ask about this stuff.
First you wanna ask yourself if you really want a supercharger or if you want to get a turbocharger. I will let you look up the differences on that, this is a link to a good thread about the differences between the two
http://www.allfordmustangs.com/forum...ercharger.html
I personally went the turbo route, if your going to be adding either a turbo or a supercharger you should spend alot of money on supporting mods or you might end up like me, i was able to drive 60 miles on the turbo before my engine is now beyond repair, or should i say, its able to be repaired but its alot cheaper to just buy a new motor.
You will need a 8.8 Rear end which can be found here,
Mustang 8.8" Rear Axle<br>Assembly 2005-2008 3.73:1<br>Ratio w/ABS w/Trac-Loc<br>Pinion Flange For Mustang V6 - FR3-6010-05AF
^^ that comes with a posi rear end so that both your tires spin and 3.73 gears already installed, on that site you can also get the same thing but with 3.55 gears or 4.10s, if your going to drive the car daily i would go with the 3.73's
The reason you need the 8.8 is because the 7.5 can not handle the power that you put out, its fine until you start reaching that 300 rwhp mark, it could go sooner or it might last forever but the chances are it will go and you really dont wanna bust your rear end, as a couple people can tell you, its no fun.
If your going to be racing the car your going to want to buy an aftermarket driveshaft, i would recommend anything from powerhouse but others have reported good things about spydershafts ( i think thats the name i could be wrong ) Heres the link for the Driveshaft you would want
PowerHouse Automotive V6 Auto 4" Aluminum Driveshaft [PHA-DS05V6 AUTO] - $519.99 : Powerhouse411
The reason you will need that if racing is because the stock driveshaft is only rated at 115mph, i cant find the video but i saw someones driveshaft bust at 120 mph on a dyno, mine personally was fine when i went 138 mph but im not going to do that again till i get a new driveshaft.
Now here's something you can decide on... i lost my motor due to burnt up cylinders and a blown headgasket and most likely some more damage, the headgasket alone would have cost close to $2,000 to repair, if you go to
http://supersixmotorsports.com they offer aftermarket heads but these kind of things are quite expensive, you could go without the aftermarket heads and what not but if this is your only form of transportation you need to be very careful with adding this much horsepower because you run the risk of being without your car for awhile.