Drivers side mirror question

I just bought a remote control drivers side mirror for my dart.
I installed it tonight and the control cable isn't long enough to allow the window to roll down.
I'm guessing that it is for a 72 or older with the wing window. I'm using 74 doors with the one piece window.
Ad said it came off of a 74 dart but I don't think so. Anyone know if there's a difference?