Yes there can and we have documented where one suppliers (lets call it the first one) bolts get mixed in the supply bin or on a car with the second suppliers. Of course this would not typically lead to three versions on the same car on the same part.
Of course what bolts were available depends on where the car was built (often different suppliers for different plant) and when the car was built. I'm guessing it was built at Dearborn
So as a place to start when and where was your car built?
Might want to consider including this information and some other helpful details as your signature that way it is automatically included every time you post or ask for help
BTW the pictures of the head markings really are not clear - at least for me in your pictures want to make another try at that or describe the head markings for us. Looks like possibly flags and PSC head markings
