^^ Dart Info.
Have you already looked at the factory manual to start out? Here is the basic ID info page.
Also, the Historical service Stellantis offers does still work but don't always expect to find anything. They responded "no information available for your car" to my request for a 1964 Dart info. They were responsive but could not find any info.
It would help if you posted a photo of the fender tag and VIN.