Rear frame rail differences

Well, i did a search and i could not find any good pics of the rear frame rails for a '74 Dart.
What are the differences between the years of say '67 to '76?
I do know about the impact shock absorbers but have no pictures to reference to the actual differences in width, design differences etc.
I would love it if someone posted some pics of them.
My cars are 3 hours away so i can't see on mine.......
Thank you in advance!
Tom.