The only thing I can think of where that may have came from is out of another guys shop. So many rebuilders throw all the parts they have to every engine in one pile. This is perfectly fine but mabe they guy filled the pan with parts and did not get them all for some reason. If you are throwing all your parts in one pile like that always make sure you have everything. If I were you I would pull the valve cover and side cover just in case there are more surprises.
