[FED 387]

Depending on the mileage and "IF" the glow plug harness has ever been changed those little wires disintegrate over time and the plug (plastic) at the valve cover gets brittle and cracks or just melts, and the valve cover gaskets start leaking a little they get brittle--- Get either the Ford OEM (very pricey) for the Dorman gasket/wire harness buy the whole thing they sell them by the EACH no set of 2 here-- don't buy any of the gippo versions you will be sorry later on--- plan on spending about 4-5 hours to replace them also while you are in there you might want to consider replacing the glow plugs at the same time get the
Motorcraft or Beru should run about $80-90 for eight ---STAY AWAY FROM AUTOLITE GLOW PLUGS pain in the *** job but if it has to be done you might as well do both at the same time--- If you ever replace the batteries ALWAYS replace both at the same time----check the starter too if the truck has a lot of miles they should crank over really fast when you hit the key ---FED 387