Spacer plate in front of leaf spring hanger

Hey guys, thanks for the feedback. If one side sits more forward in the wheelwell, does that mean the body is not the same from left to right? I would assume if the rearend was not square to the front end that the car would dog track down the road and not drive straight. I did a quick string job and the wheelbase was off from side to side by over 1/2" without the spacer, so I can only assume it was done to square up the rearend in the car.