Motorcraft gold is the only way to do it. There is a chemical in green antifreeze that literally eats the surface of the head gaskets away an causes corrosion internally so gold is the only way to go in a 6.0

Well to play devils advocate here... there are a lot of guys that would argue that motorcraft gold is the root cause of oil cooler cloggings.... thus why a lot of guys switch to an ELC.