Rear end identification

[hurricane]

Hi everyone, I need to know is there a way to know for sure if a rear end is out of a GN ?
Reason I am asking is I know someone selling a 12 bolt, but I was told GN had a 10 bolt,
This person swears it out of a GN.
So is there any codes on the rear end that would give me this info ?
Thank you everyone and enjoy your rides.

 

[ve3oky]

I'm no expert but the shape looks very different, and yes the GN's got 10 bolt 8.5's.

 

[JBreu]

If I'm reading this right, someone is selling a 12 bolt from a G.N. ? That is very possible , maybe it was swapped in there for some reason. But all Grand Nationals had the 8.5 ten bolt rears, like the second pic above....