Thats not how gears work Ron. You don't get to choose what speed speed you are going for a specific (2100) RPM. I suspect what you meant was that 2100RPM is a good cruising speed, but you can cruise at whatever speed you want. As written it does sound kind of funny.
Out of curiosity, do you know what size tires you are running? A 2.73 is pretty high gearing for most of these trucks and I have been curious how tall your tires were.
