Dunno anything about Mustangs but I read this the viper board:

About the 03' : "Bone stock, the car dyno'd 373rwhp and 381rwtq, and I ran a best of 12.77 @ 111"


http://img34.exs.cx/img34/6114/DSCN2193.jpg

"here's one for a mildly modded 03 Cobra 2.93 pulley,Custom tune by James,MAC Pro-Chamber,Stingers and K+N FIPK"