Steeda is right....
A chip WILL NOT be able to compensate for the speedo on a 96-98 GT or Cobra.
The options are the speedo gear or the Speedcal, both available from Dallas Mustang.
Depending on where you buy the speedo, it will cost you anywhere from 15 to 20 dollars.
The Speedcal is around one hundred dollars.
Hmmm, I wonder which one I would buy?
__________________
Uncle Sam
"What the hell is up with all the gauges?
Calling Captain Kirk, your ride awaits... Phasers on stun...."