need just the nut seem to of misplaced mine 
thanks!
Edit:
you can buy them from here but that's abit expensive
http://www.latemodelrestoration.com/item/N803226-S426/1979-04-Mustang-Motor-Mount-Nut

thanks!
Edit:
you can buy them from here but that's abit expensive
http://www.latemodelrestoration.com/item/N803226-S426/1979-04-Mustang-Motor-Mount-Nut