What cam should I get?

Pay no attention to advertised cam durations, only pay attention to the ".050 lift duration figures. I would strongly suggest nothing much over 220 Degrees at .050". Max lift will be determined more or less by the duration, probably not much more than .470 or so. Your motor is small in displacement and while higher in compression ratio it wont overcome a much larger cam. It all has to do with your static compressionratio, engine size and cam. A split pattern cam would be my choice. Something like the extreme comp cams or the older but still good crane econopower series. All will work with your springs in all likelyhood. Do a search on 1966 D Dart which the factory screwed together back in 66, this will give you an idea of how much they thought was optimal.