[lutach]

I would go with 1521/1.5D or you can even go with the 1521/1Y. The 1515/1Y and the 1515/2D will suck more AMPs than the 1521/1.5D. You will absolutely love the torque which will make the truck get up to speed much quicker. The 1521/1Y will have more torque then the 1521/1.5D and if you feel your speed is not enough, just try a bigger pinion. Right now I have my truck geared for around 35mph+ and I only see spikes of 75A.