[Bigger is Better]

Maybe to help isolate it to the springs or front suspension you can laydown on the side of the car and measure between the lower control arm where the bump stop is and measure up to the frame on both sides. Keep in mind an issue on the rear suspension can still effect the way the car sits in the front but you would see that most likley. If the distances are the same then you can focus on a body issue and if not rule that out.

Some other things to check is are the springs in the upper seat properly. There is a ring of metal that drops from the upper frame rail wall that locates the spring. You can catch a spring up on that some times and that will make the car higher on one side.