You must be misunderstanding how those work, or are mis-counting the gear teeth. there is not "one of two positions marked." There is only one position that covers the RANGE of gear teeth that you have installed.
I believe where the arrow in the diagram points to "6' clock" there is a bump to act as a pointer. Note in the diagram it says, 32-38. This means that if you have a 32, 36, or 38 tooth gear, you point the plug in that manner.