I get the skepticism and as I was not in the truck at the time, I can only account for what I was told by Dave. He may have an in cab vid but not sure.. maybe he'll see this and chime in.
However, I've seen several stock trucks fly by at the electronic limit and can say that his "claimed" pass was significantly faster.. scary fast. It's also worth noting that the straights down here are pretty flat and last for miles. The hard packed sand also allows the truck to hook up pretty well. That said, I'd believe that even a de-limited stock truck would be capable of achieving speeds around 130 relatively easily. I don't know of any real world testing on this.. but based on feel, I'd think that it's capable of pulling all the way through 5th.
But I guess we'll just have to film it next time lol