How heavy is your truck? Is it stock or does it have a bunch of aluminum on it. What I'd be concerned about is the motor. The 9L in a truck might get too hot. Many have gone to the 7XL for that reason, but the 7XL pulls more current.

I'm running an 8L in my relatively light buggy and haven't had any problems with heat. I like it better than running the 7XL because I find that it has more zip.

Taking a guess, I'd say that if your truck weights more than 10lbs or so, I'd say go with the XL motor and get an esc that can handle it. The Mamba Max does well on anything up to 4S lipo, or the nimh equivalent in voltage and they are inexpensive.