The gearing I have is 48spur/16pinion for running with 4S. That gives a ratio of 3. If you read in other gearing posts lots of people run the same ratio, as in 45/15=3 for a 4S batt. Power and handling is great with this setup as well as the run times. In a small and tight technical track I get 30mins runtime!!! Now if you need more you can always experiment with a couple of teeth down on the spur, or up in the pinion.

For the ESC I'm running the Hobbywing 150A pro not the hobbyking.

Hope that was helpful.

hi, just saw your messages. Sorry for not getting back to you.
In regards with the ESC, I couldn't be happier with it. I've run others in the past and now I'm running against others of course like the mambas and the tekins and mine and a buddy's (same) runs cooler everytime. You will not even notice heating.

As for the pinionm dont worry about. The reason it is long is because this conversion allow you to use the centre diff as is. To achieve that you need a long shaft pinion. A normal pinion would not reach the spur gear.

If you notice for example the Losi conversion has the central diff looking backwards, plus it has inserts to raise the diff towers so the spur wouldn't touch the chassis.

So in little words, you made a very good choice for the conversion.