Dumb question - difference between Dodge and Plymouth

The earlier you look, the more differences you will find. As the decades went by, they all figured out that the fewer specialized parts you needed, the cheaper any combination of cars was to produce. Dodge Brothers cars were mid price point. Plymouth were similar but known as a cheaper line. Chryslers were top of the line price point. AS everyone merged, the parts got less specialized where today it's rare to have anything "unique" or "special" over a wide range of models. By the time of the muscle car years, almost everything in equivilent price levels used the same parts in terms of mechanicals. Engine ratings were slightly difference mostly because of packaging - meaning manifolding and tuning differences. Then there was production line changes vs advertised info, or parts shortages that forced changes.