Wheelbase question
 

My 1984 300SD (W126) tends to drift to the right and sort of returns out of right turns. This happens at any speed. I think this is caused by the crown in the road. I was measuring the wheelbase of the car, and the right wheel base was 114 inches and the left wheelbase was 116.75. The owner's manual says it is 115.6. The car doesn't seem to have been in a wreck before.

What kind of problems will uneven wheelbase length cause? Does the car's wheelbase have to be corrected? How would it be corrected?