If you hear the slightest ticking, it probably needs full timing chains, guides, cam phasers and chain slack adjusters. For the good stuff you are looking at $1,000 in parts alone. While it is apart, best to put in a new oil pump too, another couple hundred there. Put 5-30 oil in it instead of the 5-20. Ford started with that thinner oil for mileage purposes, but it lead to all these other issues later out of warrantee usually @ 100,000 miles (but some sooner/some later). If you go to the expedition forum, you will get detailed answers.
https://www.expeditionforum.com/