When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I'm still saying lower intake bolts/gasket, but in one of your pictures it looks
like it might be coming from a freeze plug (that's not in the picture).
Get a used oil analysis done to see if coolant is also leaking into the oil. If the UOA confirms an internal leak, then it might not be such a good idea to put off the repair (think bearings).
Wherever the leak is coming from, it looks like the top end is going to need some fresh gaskets much sooner than later. Regarding the procedures(s) involved, the Ford manual is a good start. But then there are of course those "other" things that aren't in the book, which I tried to address when I documented my own 4.0L gasket woes and subsequent repairs.