yep join the club, I also have constant ticking on my 3.7 Mustang. The strange thing was that it started after 5000 miles, when I had my first oil change. From what I understand, these Duratec engines from the factory have break in oil which has a high zinc content which muffles this natural noise, I just don't like that it's hidden when you go to test drive it new at the dealership. This is another I don't like synthetic motor oil, I used to have a Ford Focus that ran thick grade conventional motor oil and it idled really smooth. Synthetic oil is like water, I want thick sludge that silences the drive train noise.
Retired but not forgotten
2014 Mustang V6 Performance Pack, Airaid CAI, Automatic 3.31
stock 0-60: 5.8 seconds
tune and cai: 5.2 seconds