I found this in a skyjacker section:
Make sure you park the vehicle on a level concrete or asphalt surface. Many times a vehicle is
un-level (side-to-side) from the factory, but usually not noticed until a lift kit has been installed
which makes the difference more visible. Using a measuring tape, measure the front and rear
(both sides) from the ground up to the center of the fender opening above the axle. Record below
for future reference. (NOTE: Due to OEM inconsistency and the available options, the amount of
lift gained by this lift kit can vary as much as 1/2".
Maybe it was that way before the kit?
Mota