If you want to race stock (not brushless) and not spend a ton of money I would recommend a Novak GTS speed contrtol and a tuned Cobalt (Co27) motor. Spur/pinion is kind of up in the air but the stock 87T spur with a 20 pinion is probably a good place to start and go up or down on the pinion from there to suit your track and motor. If you end up with a higher RPM motor like a Monster or Epic X (not my first choice for dirt) then maybe start lower on the pinion - 19 maybe 18. Again, ,it is kind of trial and error but I think this is a good starting point.