Shock plate differences?

[moparmarks]

Also here is a 71 Cuda original Dana car with it's Dana plates

 

[SGBARRACUDA]

As far as fitting 8 1/4”, 8 3/4”, Dana 60 all the same. May look different but they interchange.

 

[cudamark]

The main differences I've seen for various years and models (not counting minor appearance changes) is the location of the shock pin. This might be important with ground clearance and which shocks you buy.

 

[YY1]

73 and up B/F/M/J "ISO" plates can be used by grinding down the area around the hole and welding in a thick washer if they are free/cheap enough to warrant the labor.