Do the oil pump and Shaft while you are at it, but dont buy a part store pump! I rebuilt my first motor put a 'new' pump in and it locked up snapped the shaft, and you know what a pain the 'double sump' oil pan causes when replacing the pump.
I would get a new pump from ford and the motorsports shaft - dont get the regular shaft because they snap
It's good insurance for about $55 pump/shaft!
Good luck!