My 73' roadster has had a bad lean since I bought it. Swapped the rear springs left to right.....no change. Installed new rear springs.....slight change. This past week I rebuilt the front end and swapped the front springs left to right, EUREKA, she now sits perfectly level. Not sure if it was the spring change or replacing the suspension bushing that made such a big difference. Maybe a combination of both. The springs measured equally but no telling if the left one was fatigued more than the right. I know for sure the bushing were in horrible shape. They were rock hard and literally welded to the upper trunion and the wishbones. I am surprised that the suspension moved at all. Maybe the bushings were restricting movement enough to cause a lean. Anyway, those with a lean might consider looking at the front of the car rather than the rear for the source of the problem.