I was experiencing the same noise on startup on the driver's side on my 2014 5.7 a couple years ago. Took it to the dealer and they diagnosed it as broken bolts and a cracked exhaust manifold. They replaced it and the noise went away. Started to hear the same ticking on the passenger side several months ago. Again, took it to the dealer a couple weeks ago and the same issue happened with the passenger side exhaust manifold and bolts. They replaced the manifold and bolts and it's all quiet again. According to the service manager, there is an issue with this generation of 5.7's where the manifold bolts break and then cracks in the manifold soon follow. When this happens, they replace the manifold and bolts with an "upgraded design". The driver's side happened at 108k miles and the passenger side at 147k miles. I'd check the exhaust manifolds carefully before launching on a lifter replacement project. Further info he provided was that they had to TIG weld a nut onto the remaining piece of the broken manifold bolts still in the head in order to back them out. Fortunately, I have the Mopar Lifetime warranty that covered both of these repairs as these were jobs I'm glad I didn't need to tackle on my own. Good luck and keep us informed on what you find out.