Short answer is no I can get really involved if you like but a lowering kit is the only real way.
http://www.streetfightersinc.com/LoweringKits.htm
To get more then 1/4in-inch of play is what your going to have to do. Rear springs are more for preload adjustments, damping/rebound all that fun stuff you really don't get too much height/lowering out of them.