When I purchased BG she tilted a little to the left, like there was a 500 pound driver in the driver's seat even though she was empty.
Like the Model T and Model A Fords, BG has leaf springs. However, unlike the Fords which have two transverse springs (one over each axle), GB has four longitudinal springs (two on each side, or two in the front and two in back).
After first checking to see that the front bumper and the rear bumper were parallel with the body parts, I measured the distance from the garage floor to the bumpers. The left rear was 1/8 inch lower than the right rear. The left front was 1/2 inch lower than the right front. So I jacked up the left front until the bumper was level. The back was level too. So the problem is the left front spring.