Freeze plug pushed out

i do hope you check the heads for cracks before spending bucks on them . but your block could have cracked during a overheating . its a ford i gather . not many of them come down my road , did a friends ranger v6 once . we ended up replacing the whole engine after he ran it hot just once . heads had 30 plus cracks in them . if you heads are still good , grab another lower end and transfer parts . after all there were more the a few million mustangs built to rob parts from .