I did not see much on the original stock one I removed; the wear seemed to be pretty much in the links. But I got a whole set just in case.
To the OP, when you say 'pinging', do you mean that the sounds has a ring to it? Another /6 tapping areas up front are the fuel pump; the pump arm gets a bit loose and is smacked by the eccentric; I had that one recently. I could put a long screwdriver to my ear and to the pump and really hear it loudly.
And valves are a really good source of funny taps and knocks. Try an adjustment on them.
Lastly, exhaust manifold leaks makes some good noise: I had one that squeaked at idle when warming up. The exhaust condensation would get into the leak and squeak at each exhaust pulse like blowing through a blade of grass between your thumbs! I was imagining metal being scraped away at each squeak 'til we figured it out.
