It's dripping just inboard of the starboard side valve cover and landing on the valley in the engine - most of it probably was burning off as I drove. I'm not counting my chickens, yet, but I'm sure as heck hoping this is the problem. I'll wait on buying the plug adapter. Once I get the oil analysis back - if all is good (at least I know coolant isn't going into the oil) then I'll drive the truck and see if the leak has stopped.