I just changed the oil pump cover o-ring. Pulled batter and box, fan, shroud, crank pulley, idler pulley, and center plug on distributor. Put everything back together with no problems and just found this little part (on left, oil pump cover screw for reference size) laying on the floor. Clean, not oily when found. I don't want to start it without knowing this isn't a part of the oil pump or something. Any ideas?