new 71 dart swinger owner

Welcome to FABO, the car looks like a '72 to me too.
Look at the V.I.N. on the dash, it should read LL23_2_XXXXXX for a '72 and replace the 2 with a 1 for '71.
The 4th digit is the engine (B, C, or G) and the 5th digit is the year. 6th is the build plant, and then the rest in X's is the sequential serial number of the car.