My friend came to me with questions that I have not been able to answer. His 1956 Oldsmobile with original 324/4V is a great runner. Starts good, too. The 324 was rebuilt some 20 years ago, but we doubt it has 5000 miles on it since. His questions are regarding a miss that begins to show up after 15-20 miles of driving. It begins and it barely noticeable. It will progress to the point that it seems like one cylinder is dead. If he stops after a short drive and lets the engine cool, it will not be missing when he restarts. But after a bit more driving, when the engine gets up to temp., it will start to miss again. When cool, it runs just perfect. I know he has changed the plugs. I don't believe much else has been changed. could it be a plug wire, the coil, the condenser? I feel it must be something electric. I can't believe it could be points. I also can't imagine it to be anything mechanical? There is not a strange noise, other than the miss. Good oil pressure and the temperature stays steady after the themostat opens. I want to help him avoid throwing money and parts at his car. any suggestions or ideas?