Pro-Hawk said:
This question always comes up on Ford Ranger forums. One post states that the easiest way to get around the governor is to pull the fuse that protects your instrument cluster, which includes the speedometer. If the speed sensor never reports being at the max speed, the governor never shuts the fuel delivery off. But most people want to see their speedo. One poster said he wired a switch so he could take the Ranger up to 97 mph, the open the switch and then go past the limited speed of 98 mph.
I never tried this personally, but I thought I'd share it. It might apply to Mustangs too.