[rosenkranswa]

Not on a Model A, but I did a major tune-up on my '42 Jeep - plugs, points, wires, distributor cap, rotor, etc. - everything except the coil. So I'm at an event and the thing won't run right, get it home and pull the coil (not an easy thing to do on a Jeep) and its substandard according to Les's book (yes, the Model A book which I find is pretty generally applicable) so I replaced it and voila, no more problems. Should have known from my Model A's - first things I suspect when an A runs rough are the coil and condenser...