DML FAQ : Electronics : What is the speed limiter on the Mopar Performance PCM?
Mopar Performance computers (PCMs) have their speed limiter set at 255 (basically removed). MP assumes that if you're going to buy a racing PCM you know what your limitations are in terms of tires, heat, velocity, and stability of your vehicle.
The rev limiter is still set (it's already higher for a MP PCM, but not unlimited), but that can be changed depending on application. Mike Leach, in association with Ron Zimmer, can provide those changes.