I am having the same problem and I can tell you what not to do, mine was 3/4 of an inch low in the front, and a half an inch low on the right side, makes for a huge dip to the right front.
I recently got tired of the lean and bought a new set of front springs, this fixed nothing, so I installed a 3/4 in spacer in the front. it still looked and felt like the front right was diving.
I decided to fool around with it this afternoon and my measurements showed that the right rear spring was 1/2 inch shorter than the left, upon closer inspection It turns out that the leaf packs did not have identical small leaves. I dropped my rear end, and dismantled my spring packs. I discovered a 1/2 inch difference in curvature of the two small leaves. I dismantled my old stock spring packs and decided to try to replace the smallest lift spring with the two smallest from the stock pack.
this netted me another inch of lift! oops! I checked my measurements again, and the lean is now exaggerated. 1 inch higher on the left than the right.
I am thouroughly aggrivated now, because it appears that I cannot fix it without buying new spring packs......and I am currently an unemployed college student.....again. anyone have any solutions that will allow me to have the same spring rate on both sides and not buy new packs?