First how much do you have to spend.

If i was you i would rebuild the bottom end (stock parts), then the head would have done P&P, 3 angle valve job, some stage 2 or 3 crane cams, aem cam gears, upgraded springs/retainers, and mill 30 thousandths. Also i/h/e for bolt-ons.

That setup will easly push low 13s in a light crx