Originally Posted By: bullwinkle
Any of the above, although the MC blend might be (slightly) superior. I would add Super Tech full synthetic to the list as well.
Agreed.
If you really wanted us to pick one from the two you listed, I'd go with Motorcraft. Nothing against MS5k, I really like the oil, it's just you're asking about oil for a Ford so I default to Motorcraft because of the Ford/Motorcraft relationship. But MS5k is an excellent oil, so if you chose to save a couple bucks and go with it over the Motorcraft I doubt your engine would ever realize.