Tony----
I think you're in luck. First of all, I confirmed that the correct GM part number for your application is 3888366, as I mentioned in the earlier post. Second, I have an original, 3888366 in my collection. I examined it and it has the markings which you describe. I believe that the "66" probably represents the last two digits of the part number. That was most likely the "broadcast code" which facilitated the easy and quick identification of a part for installation by assembly line workers.
I think you're in luck. First of all, I confirmed that the correct GM part number for your application is 3888366, as I mentioned in the earlier post. Second, I have an original, 3888366 in my collection. I examined it and it has the markings which you describe. I believe that the "66" probably represents the last two digits of the part number. That was most likely the "broadcast code" which facilitated the easy and quick identification of a part for installation by assembly line workers.