Something a lot of mustang owners seem to skip is the alignment, which IMO is the most important part.
It's like building the hell out of your engine and running a crappy canned tune.
Most alignment places just set the camber at 0.
I can't stand it, my wrx which runs -3 upfront turns on a dime, for a street driven car I would recommnd around -1.5 as it's a middle ground between performance and tire wear.
As long as the the toe is zero'd out, tire wear will be fine. I highly recommend more camber on these cars, makes a world of difference and helps eliminate alot of understeer that these cars have.
Cliff notes; run more camber for optimal performance, -1.5 front is my suggestion