The dealer pump will be a change up. It will likely Not even resemble the original.
I work at a dealer and it is unusual for me to work on car that is older than 5 years. Let alone 40 years.
Even when 80's stuff comes in, we usually get the parts from a jobber store.
That's a nice looking dart. If I were you I would want a quality replacement part (like a carter) and not be concerned about anything else.
If it's a car that is driven, it's value will not be affected AT ALL by the brand of fuel pump you use.
