how to identify

what year steering columns are? i have the ones i brought home from moparty and have one from a 70 dart and a 71 dart(i think). how do i identify what years they are? all are column shift and i know that the blue one i have came from a 70 dart that i stripped out.
Some photos of the columns might help us I.D. them. In 1970, the key was released by putting the shifter in Park. Later columns had a lever you had to push to release the key. The lock cylinders and housing also changed after '71 from a spring loaded blade retainer, to a round pin retainer. As in many years, the changes may not happen exactly with the model year change.