respectfully, I don't think that is correct. The mixed year was 70 with CA emissions cars with the 4 tube tank, tower etc, and the rest of them with just a vent at the top of the fill tube. I think they all had the 70 style CA emissions set up in 1971.
Assuming the car can be confirmed to have the same VIN as the title - what a great body to start a project with!!! the floors look excellent and and the top doesn't even look rotted under the vinyl.
By the way, side trim attachment - 70 Darts have holes in the fenders, quarters and doors for white translucent clips with little pegs pushed through them to hold the side trim, where 71s had posts welded in place with plastic clips that slid over them. pop off a piece and we'll kmow