I've done what Dave suggests and it gives you the answer you need to the question. In talking with people you realize that the earning potential has a lot to do with who owns and/or operates the truck, how the overall economy is doing, how long you stay out, and a lot of small things that add up to different potentials for different teams. Add to that a large dose of luck for anyone in this business, and you will see that there is no secret answer to the earning potential question.
With all that said, though, my sense is that a straight truck team staying out 3 to 4 weeks at a time can gross $150k to $180k. Some do a little better probably. Others do a lot worse. If you're doing a 60/40 split with an owner those numbers probably give a reasonable ballpark.