XRAY - Model racing cars

Hello!
We often race outdoor, so 64p Spur and Pinion isn't very good idea.
Is it possible to fit 48p Spur/pinion to X-12?
What preferred pair will be for 13.5t motor?

http://kimbroughracingproducts.com/stor ... ory_id=199

If you use a 72 tooth spur with a 44 tooth pinion, and if you use a 42mm rear tire, this will give you a rollout of 80mm which is a good starting point for 13.5T blinky spec racing.

Thank you very much.
I will
Try found those pinions, unfortunate race will be next week, and our local shop don't have enough 64p big size pinions, that's might be problem:(