Not certain about the ticking, though my engine ran considerably louder. This was difficult to tell as the problem had been progressive. After the new headers were on though, the reduced engine noise was pronounced. A crack usually appears at the point where the two down pipes converge into one. Check this area when the engine is cold, as once the manifold heats up the cracks will sometimes close up on you. Other than that, the engine may feel a little sluggish compared to what you are used to, though the best diagnosis will be a visual inspection.
If you do have cracks and are to replace the manifold, I strongly recommend the Banks Torque Tube. Their work is beautiful, the welds are clean, and it comes with a great warranty should you ever need it. As for the install, it is relatively simple until you find that one bolt somewhere in the middle of the flange. Try not to get frustrated, just plan on spending some quality time making 1/4" turns with a crescent wrench.