IMO, while it could prove to be an interesting project...probably not worth it.
If brutal bottom end is what you're after, along with respectible mid to top AND good fuel mileage...look into either the Radical/OPS T version engine or the Trinity ExTech .21 or .24. Pair either up with a Werks or Sirio 2013 and you'll be very pleased. I mention these in particular a I have experience with them. Im sure others would recomend other engine combos....