Rear inner frame rail dimension CJ7...?

[83power]

As you can see, I don't have much of a rear frame.

Could someone provide a good inside measurement of one of the frame rails,
View attachment 16165

View attachment 16166

 

[Torxhead]

My '86 has 32 1/2" inside the frame rails just above the rear spring shackles.

 

[83power]

I guess im not saying it correctly, I need the inside of the frame rail, should be around 3" x 4", but I would like to know the exact.

 

[Torxhead]

2 9/16" at the spring shackle.