What motors are you looking at, specifically?
Im assuming you have the RTR Losi, that motor was meant more for use on 3s, as its a bit of a dog on 2 cell.
Its the same motor as the Castle 1415 2400kv, and the esc in the RTR is a rebadged Castle MMP.
You can either throw a 3s in your truck and watch it come alive, or go with a smaller 4 pole motor and watch it rip on 2s.