360 timing ignition woes

Did you check the timing chain for stretch yet?
As of yesterday day the true tops dead center is spot on with the balancer mark. All of the grounds for the engine, ecu, battery are good bare metal. I do have one exhaust lobe on if I remember correctly hole number 7 that wasn’t flat but wasn’t great either. As for checking for timing chain stretch the only method I’m aware of to check this is to rotate the engine back and forth while watching the rotor for play and that does not show any warning signs. Thanks everyone for the replies I am at a loss