98 Camaro V-6 Top End Noise When Cold

I have a 98 Camaro, 4.3 V-6 with 105,000miles.
Lately upon startup and until it is warm, there is noise coming from
the top-end, to me it sounds like the rocker arms (or at least that
area) it quiets down when it gets warm. I am curious how concerned I
need to be about the noise or what should be done about it.

Service Engine Light did come on but has since went off,,,, so not sure
if there might still be a code showing if I take it in to a shop.

Other things to mention, the noise appeared only after I had run it out
of gas a week ago. (had not done that since high school) but I was
trying to start it until I realized it was out of gas, now am wondering
if I hurt some components from lack of proper oil flow.

Was running a bit rough from time to time upon startup before the gas
incident, but I did change the fuel filter and oil just a few days ago.

Tidbit,,,,, at 90,000miles, hit a pothole and lost reverse and 2nd
gear, after googling, I found the 4L60E transmission had issues with
broken gear and my repairs cost $1,800. (so if you lose reverse and
2nd) there is your cost estimate.

So if anyone has comments about my top end (rocker arm area) noise upon
startup, please share.

Thanks Much!!!