[olddog]

I have not read all of this thread. Skimming back, it looks like you tried a different (Known good distributor). If you have ruled out all of the ignition parts and are stumped, pull the valve covers and check your valve springs carefully. I have seen broken valve springs cause what you would swear is an ignition miss.

My son's Lincoln dropped the valve into the cylinder for a spectacular ending before he found his miss.