How To Replace your Lower Column Bearing: Better and Cheaper!!!
The service manuals are just listed by the year and make, not the model. The '70 model year cars had reverse lock out rods incorporated into the steering, so you'd be better off using the '73 Dodge manuals from that page.
I have the '72 Dodge chassis and body service manuals, but I don't currently have a way to host them. One's 329 mb and the other is 116 mb. That would be the correct one for your Dart.