[MetalMan]

You may need to experiment with gearing. If you bought a 6-pack of Robinson 48p pinion gears, you could try anything from 16t-26t or 15t-25t in even or odd increments. This is what I did, and I will have to figure out the gearing on my Rustler. If I had to take a guess, I would think stock gearing (18/87) should at least be a good starting point. One thing to keep in mind, though, is that the motor could get hot from being undergeared or overgeared, which is why I suggest a set of pinions that you can experiment with.

The380C 6L should be slightly faster than the 8s due to its higher kv. It may actually end up at the same speed since it is a smaller motor. But, it might feel like it accelerates faster, which is due to the smaller rotor.