How to get to this 'stance'

So I have a couple question on this subject, only, I'm asking for the opposite reasons. I want my car to sit kind of high and level, not as extreme as a gasser but high... Its a 440 in a '67 Valiant. Why couldn't a person just mount the front of the leaf springs below the framerail rather than cutting into it to mount the boxes? Also what size torsion bars should I use and what vehicle would be a good place to source them from? thanks in advance for any suggestions.