Yes the orginal factory tune is what would create that. And yes, Ford does have an updated re-flash for SVTs.
You can visit your local Ford dealership and see what they say. If they determine that you have the current flash of the ECU. Then it is a matter of custom tuning your ride.
Sorry for the late reply, but yea, many of the SVT owners have gone the custom tune route. And we have tuners on the site that can help you with that. 1TurboFocus aka Turbo Tom, who is also a vender on this site as Focus-Power, is a popular tuner that can help you with that issue.
You can find him here and then PM him or create a new thread in there for him to see it right away. CLICK HERE TO GO TO HIS THREAD AREA