Just finished fixing the ignition system on a nice '55 Ford, the previous work done was less than ... knowledgeable
This car did not run right, had poor engine power and simply not anywhere near correct.  I suspected the spark advance, tested the distributor 'pancake' first, many of these now are failing, those diaphragms leaking.  I test with a piece of hose, suck on it then seal the vacuum with the tongue, it must hold vacuum and if it doesn't ... get a new one.
Next was the very important vacuum spark control valve that screws into the back of the carb', examination of this one showed that somebody had put in a typical power valve ... just not a good idea, not going to work.  I replaced that with the real thing, these can be ordered new from Mike's Carb' Shop online, they have them in stock.
Now that '55 runs like a million, all it takes is a working vacuum advance system.
Warren.