73 duster doors - what's the difference?

I did just get the 74 doors out and the mechanisms seem kind of the same but I think it's the vertical pole in the 74 doors might be a vertical track in the 73 doors? I have all the guts of the 73 doors I just don't have the actual metal structure peace I must have tossed that.
I believe the structures are the sme,73 window regulator mechanism is different. I put 73 regulators into 75 door shells with no problems