[drolston]

Looking at the jacks and the bottom of the fuel tank, it looks like the chassis may not be level. How about a frame to floor measurement on both sides?

Another thought: if the car was lifted ones side at a time, it could leave the rear axel hanging cockeyed because of friction in the spring and shackles. Put a crowbar or something between the right shackles and see if you can force the rear end to the left far enough to center with shackles at equal angles. If you can it will probably stay that way and all is well.