mr. fuss, welcome to Just Answer!.
There's a good chance your noise is an exhaust leak if:
It seems louder on a cold engine, decreases in volume as the exhaust heats up.
It becomes immediately louder as throttle load is applied to the engine.
Disappears briefly as throttle load is released.
Operates at 1/2 engine speed.
The rear two exhaust manifold attaching bolts tend to snap on the 4.7 engine, leaving no clamping force on the gasket which opens up a small gap at cylinder #7 or 8 (depending on side). While it may sound like a mechanical ticking noise, it's the exposive nature of exhaust leaving the just-fired cylinder that creates the sound.
On a cool engine, reach toward the back of the exhaust manifold heat shield on both sides and see if it's loose. The same bolts that hold the shield close to the manifold also clamp it to the cylinder head, so if you find you can pull the shield away from the engine... you've got broken bolts.
The good news is that they break off far above the cylinder head surface in this model year, giving you plenty of material to grab for removal. With no torque applied to the threads, they typically just spin right out although gasket replacement will probably be required, requiring manifold removal.
Write back if you have any questions, mr. fuss. I'd be glad to help any way I can.