What do you guys think about this noise?
 

A guy called me to look/listen to his truck. Here is a video of the sound. Any input or thoughts about what this may be would be appreciated.

Hard to tell but sounds like it could be an exhaust leak (maybe at the manifold/head connection)

That's what I was thinking. I couldn't pinpoint it or see under there real good.

If anyone has any suggestions please let me know.

look for a hard line towards the top of the motor thats what cracks all the time.
All the 4.6, 5.0 and 5.4 motors are notorious for it..

I believe its a egr line or pcv line or something like that...

Should be to the top of the valve covers to the intake mani

They're also a bit notorious for blowing out spark plugs.

That's the famous sparkplug blowout syndrome you are hearing, That and exhaust manifolds cracking are the two biggest problems with this series of Ford motors (Triton). Dealers just like to replace the heads but there are aftermarket alternatives that are widely used. Unfortunately this is a very common problem on the 4.6's and the 5.4's.