B4 Newbie Doobie Doo advice please

[Alfonzo]

Just got a second hand B4. Looking for recommendations for pinion / spur to suit a Lipo & Mamba Max 5700kv motor combo. Think that's equivalent to a 9 / 10turn ish. I've currently got it on a 19 pinion and I'm not sure what the spur is, perhaps kit (81t?) Car will be running on indoor carpet.

Ta

Oh, and any other newbie advice, like 'always check such and such or the thingybob falls off' or whatever

Thanking you.