[FWB]

sounds like the gasket failed at the coolant passage in the front, letting water seep into #1 runner, get a good set of replacement gaskets from keith and use motorcraft diesel sealant on them and you should be good to go.
been there....this will be a good time to check to see if any pushrods are rubbing the intake too........this was causing issues with mine.....16 sticks pushing on the intake doesn't make for a good seal......


fred