Highly unlikely that the LS V8 chain has stretched alot, they rarely if ever cause issues. Never heard of one even jumping time nor has the tone ring on the crank or cam gear ever been a problem.


I would inspect both the cam and crank sensors, check wiring to both and make sure that is alright. I would even try a crank learn to re-sync the sensors together and see what it does. Seems like replacing one or the other would be the next step and doing a crank learn after too.