Mileage varies. I replaced the stock chain and gears around 120000 miles, and I have since replaced the timing set again around 170000 miles because I had a coolant leak and I found that it had stretched beyond spec.
Just my own personal opinion, but I wouldn't really want to exceed much over 250,000 miles on a chain. You can have a car throw a chain even earlier than that though. You should check the timing chain stretch when you adjust your valves, assuming you have a model that requires manual adjustments. That will give you a good idea of the amount of stretch/wear. That still doesn't rule out the possibility of catastrophic failure of the chain due to guide/tensioner failure, etc. It's probably not a good idea to push life on chains.
I have replaced chains here in Vegas since 2006 and its just like stated above: life of chain is directly linked to oil changes.
Often they fail without any prior symptoms (or at least none that owners noticed). Changing prior saves big bucks. Once they fa and wipe out valves it's a whole new set of woes.
I recently changed out a timing set on a 2.4 Equinox (same timing set as Redline) with 140K that was rattling. Owner had only owned it for 4 months. I explained that the oil was nasty and needed changed far more often. They claim they followed the oil life monitor on dash. 15K later it was back with noise again. I pulled the chain and it was stretched and tensioner was almost maxed out. Oil system was down 3 quarts. I had the talk with her again and explained that oil must be changed more often.
Both services I used GM chain kits and and fresh 5W30 oil w Dexos. The chains were stretched to tensioners max. She was very close to an expensive failure.
There are lots of videos out there that can walk you through the process of replacing the chain before failure. Or find someone that can help.
Anyone that wants a trip to Vegas, I would love to help.
My 2003 base model, I'm the original owner, first oil life monitor message didn't come on until somewhere in the 52k mile range.
I still change my oil every 3k in all my cars. I don't care if its 5k or 10k oil.
Ecotecs timing chains have taught me to be overly cautious 😂