Coolant in around #2 and 3 spark plugs on top

I have a V10 E350 that has a misfire. Determined it to be codes 302 and 303. Inspection revealed coolant around the plug boots and had caused carbon tracking misfire. I am looking for possible sources of the coolant. I have pumped the system up to 16lbs and find no leaks from heater core hoses directly above the coils. Is there another source? It is stained on the intake near number 3. No direct eveidence of source.
Has anyone experienced this condition?
Thanks

Further inspection found coolant leak at right front coolant passage. It would then run down the manifold to the 2 and 3 spark plug wells. Intake gasket removal here I come.