Get that wrench out
What you don't want to hear, I believe these numbers are accurate and all are +/-5 or so MPH:
SXT are governed at 115
R/T are governed at 130
Daytona are governed at 145
SRT8 are governed at 160
The limiter can be raised by a programmer.
Now the qualifiers... I run mine up every now and then on open highway. Be safe and stay within your tire ratings and remember the others on the road depending on you to be safe as well. I don't want to be around when a car wipes out at 115+++MPH.