New Jersey allows anything on the freeways that can maintain minimum speed.
Some states allow anything over five brake horsepower.
California allows anything with at least 150cc displacement.
Nevada does not seem to define motor-driven cycles (5hp or 150cc) and thus Nevada simply allow anything that will maintain minimum speed.
Your DR400Z is well over 5 bhp, well over 150cc, and is well capable of exceed of the maximum speed limit, less minimum. Your motorcycle is legal on any freeway and any Interstate in the U.S. or the World.