Front grill, hood lettering, headlight buckets will need to be relocated to match the headlight bezels.
Add marker lights front and rear.
Depending on 67 dart trim level you will need to fill holes. Or drill new ones
Trunk molding and tail light openings will need to be altered.
Then the inside seats are different, door panels, steering wheel, dash pad and lower dash pad.
OR
You could leave the 67 as a 67 which is by far the coolest looking Dart of the series.