I had my Cobra dyno'ed in Memphis, Tn. at Dyno Speed Racing, they do a "lot" of Mustangs. Joe told me most stock 05-07 Mustangs dyno at 280-290 rwhp. He said that would be 330 flywheel range. Ford was sued for their advertised HP on the 03 or 04 Cobra Mustang. I think they now advertise a HP rate they know will pass on any dyno.
Dwight
