Every generation of 5.0 has inherent issues. A lot develop tick/knock. 18 and up burn a LOT of oil. The latest generation has Ford's version of DOD/MDS and also an oil pump wet drive belt with port and direct injection. They make nice noises under throttle, but it definitely isn't the best choice unless you're planning on power adders.
If it is a 4x4, check the front axle u joints. One of them can bind and create a NASTY intermittent dart.
Jack the front end off the ground, turn the wheels about half way from center and lock the hubs. They shouldn't bind when the tires are turned.