I was the first one to change the plugs, they were original... I suspect it was just a coincidence unless it was related to the misfire in cyl 3 (which I was throwing a code for hence why I changed the plugs) that was fixed with the change... I WISH i was knowledgable in this area to be able to offer more than my one experience on this one, but i did find this on YouTube a while back when i first noticed and researched it... maybe it has something helpful to solve your ticking thing
... But i am the furthest thing from a mechanic and just getting started with a Chevy (been a dodge gurl with a chevy dad my whole life).