I read in a magazine a teggy was running 12's (high) with just like i/h/e and stage 3 cams and better valve train, so yeah, i would say that they do quite a bit. and as far as how much hp you need to get to 14's:
http://www.web-cars.com/math/qtr_mile.html
I think this site can give you an idea, not quite sure how accurate it is. Hope it helps