Brushed gearing

[Miggers]

Bit of a daft question really(I used to race 4WD BITD),I'm playing with
a 2WD to get back into the swing a bit and have found a nice dirt/hard pack/dusty
with a few decent jumps and corners spot to give it some stick.
What would folks recommend for that surface and running:

Mad Rat gearbox(fully ballraced)

Standard Ansmann spur/slipper

17x2 brushed

Mtroniks 10turn limit ESC

1900 Scr Ni-Cads(told you I was old Skool)

I have been using the stock Ansmann 21t pinion,but was wondering if it'd
do better with another spur/pinion combo.