No. Spring spacers should ONLY be used to adjust ride height. Adding spring spacers WONT increase the springs firmness until your ride height is maxxed out, at which point you have no droop, and your handling will be crap... A set of firmer springs will give you the firmer rate without increasing ride height (other than your trucks weight will compress them less) You could also just increase your shock oil WT to get a firmer feel, but that can have negative affects too if you go too far (going from 30wt to 45 wt is OK, but you don't want to go from, say, 30-60 wt.....) The best thing for you to do depends on why you want the firmer springs... If you are happy with the shock action but bottom out over big jumps, you want thicker shock oil. If you have tried thicker oil but the then the suspension responds too slow, then you want firmer springs.