skyjacker full leaf packs. front measures level. the problem is the drivers side rear spring. the shackles are new factory shackles, and measure exactly the same. lift has been on since early february. d side settled within a week. got a replacement spring from skyjacker, and put it on, and the thing still was low on the d-side. switched springs from side to side, and it looked level until I wheeled it, now showing the same amount of sag on the drivers side. can't figure it out. measured the length between the front spring bolts and the upper shackle bolts, and that is also exactly the same. thats why I thought I could just level it with a 1" block on the drivers side, but I don't know if that will throw off anything in the driveline.