Ha..... the car is low milage original so I'm assuming it's from the factory. I'm only guessing it has something to do with balancing???? the original owner was also talked into the rust proofing as you can see by the black over spray.
Thanks Jon and Dennis. it seems weird I'm sure but when I work on this car I often wonder if the gm employee (that installed what I'm wrenching on) is still alive.