I've absolutely no knowledge on the subject of rack and pinion... pretty much no knowledge of most other things to be honest, but... am I missing the plot here... if you're talking of gearing the the pinion, then surely the tooth count of the pinion is essentially the gearing component?, If you go from a (e.g.) 60 tooth pinion to a (e.g.) 20 tooth pinion you'd effect a 3:1 reduction.

Or am I being stoopid?

EDIT: Not trying to answer (or validate) the question, and so this response is clearly off-topic, but just casual curiosity. Also, would think the above could avoid introducing additional backlash in a gear chain

EDIT 2: Just reversed the example tooth count above, having woken up a bit.