Well I did honestly do 110mph in mine a couple of weeks ago, I have a reprogrammed pcm with no speed limiter......
I had an Avalanche riding my bumper at 90 and so I punched it, he stayed with me until about 97 when his limiter kicked in.......
That was with the 33" duelers and not my 35" STT's and the truck was surprisingly stable at that speed. It was still climbing when I let off the gas...