I had someone on my channel with a 3rd Gen Camaro V8 that was running bad. We traded comments and messages over time to see what might be the cause. In the end, he found the crankshaft damper had gone bad and the outer ring was slipping. This part is sometimes also called a harmonic damper, harmonic balancer, or crankshaft balancer. That caused the timing to be wrong, because the reference mark was in the wrong location when the engine timing was reset. That was the clue to the problem. If you have an engine with crankshaft based timing, the engine might still perform well, except that the damper would not be functioning properly and could eventually come apart.
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