Determining Frame Year

[Allen9878]

I have a 1980 CJ5 that needs a new frame. I am in contact with someone who has a cj rolling chassis but is unsure of the year. How can I determine if it will work for mine? I don't have pics yet just looking for differences between the early 70's and late 70's early eighties. Later I will get the pic's.

Thanks!

 

[Sasquach]

The frame will have a serial # around the right rear wheel if I remember.
The early 70's frame is not boxed but not sure when it changed-75ish?
That's all I know , wasn't much was it?

 

[73CJ]

75 and below have straight frame rails - equal distant between them.

76 + widen in the back before the rear axle.