i run 4.10s in my DD and its one of the favorite things i've done to the car. i do plenty of highway driving too. as long as you don't mind it wound up fairly high, they are awesome.
2007 Mustang GT/CS: Lexi
Steeda CAI-Bama Race Tune-Pypes O/R X-pipe-Pypes Black Pype Bombs-Ford Racing 4.10s-Eibach ProDamper Shocks and Struts-Eibach ProKit Lowering Springs-DBA T2 Slotted Front and Rear Rotors-Ford Racing Front Lower Control Arms