Df-03 Keen Hawk Gear Setup Help Rqd

[tamiya monkey]

hi there i was wanting some advice, although i have had a few tamiya cars before, the only thing i have changed is the pinion gear, now here's where i get stuck. ive just put a 13t yokomo pro stock 2 motor, in with standard gearing apart from i have the slipper clutch fitted. now what pinion/spur gear setup should i use for this motor and will this work with my slipper clutch. any advice on this one would be great.