MY JK always leaned to the passenger side, before been lifted and after. Full or empty gas tank. I fixed it by using a 3/4" spacer at the rear on the passenger side.
Not sure I'd say it is a huge lean, but is why you should measure side to side differences with some sat in the driver seat. It didn't make much difference for me, about 1/4".really? go throw a couple cases of water in the front seat you will see a huge LEAN from the water alone. 100 pounds will most certainly make the jeep lean
I suspect it is more to do with the rear track bar pulling down the passenger side as it holds the axle centered, but I may be wrong.Could be because of the fuel tank and the fact that the right side is the torque down side of the motor.
Yup, it is a very easy install.The spacer will go between the spring and the upper spring seat, disconnect the rear sway bar both sides remove the right rear shock jack the frame only up you then should be able to insert the spacer. reverse