Ignitition Lock Set Difference

I'm restoring and converting over a steering column for automatic on the floor. I need to replace the ignition lock set. According to the Year One catalog I have there were 2 different lock sets. One was for 70-71 columns, the other for 72-74 columns. I don't know for sure what year column I have. So how do I figure out which ignition lock set I need to order? Is there any other place to get one other than Year One?
thanks,

We dont know what kind of car you are working on here........

I have a 73 Duster, but the column I'm working on is not from my car. Ii is one I bought to convert my car over to automatic on the floor.But I don't know what year the column is.

pull it out & post a pic so it can b ID'd & get a used one here for reasonable $$ instead of a Y1 gold plated one

Just take it to a locksmith.They can key it to the keys you have so they will fit the doors and ignition.That way you dont have to change the door locks or have 2 different keys.Rocky

The only difference I was told is the top collar section. The ones from 70-71 did not have the key releace lever on top. From 1972 and up there is a key release lever to top of the collar. My top collar section(s) have the key release lever, so I am going to go with the newer ignition lock set. The ones I've seen are around $26. Does NAPA etc carry these or do you have to get them from a Mopar vendor?

The lock cylinder release hole in the steering column is in a different position.

The lock cylinder buttons are different.