I find this a little tough to believe. I've seen stockers with plastic sprockets that ran (poorly) after some of the plastic was gone and they'd SLIPPED a tooth.
No, I mean run period. Learned this with my '74 Charger. The first '18 I owned was in a '73 Van and it doesn't count since it was pulled in favor of a 440 after the first couple of months of ownership. At 58000 the Charger wouldn't start one morning. Had it towed to the shop where I worked and found so much slack in the chain that the crank would turn about a quarter of a turn before the cam started moving. Changed the chain and she fired right up but wouldn't idle worth beans. Dug deeper and found 12 bent valves and 16 bent pushrods. Driving style may have had something to do with it since I treat the accelerator pedal like an on/off switch. I don't baby one by any stretch of the imagination, and a Mopar is the only car I've found that will take the pounding long enough to empty the payment book. Bottom line, if the timing marks are moving around at idle, the timing chain is history. Period.
