i recently tried lowing my rearend 2" to level it out. couldn't find a kit that would fit my 3" wide springs. all i could find was for 2 1/2" wide springs. so i measured the front from ground up to the highest part of the front fender well and then the back fender well. it was exactly 2" defference. so i took the shackles off, cut inhalf and added 2". put them back on, remeasured, just a slight change. still 1 3/4" defference. my question is, how much should i add to level it out?