8 1/4 rear end dimentions

I have looked all over, and can't find the dimentions for the A Body 8 1/4 rear end. I need the flange to flange, and backing plate to backing plate widths.
I have seen it on the sight but it is being hard to find.
I am going to look at one this week end, and don't want to buy the wrong one.
Thanks
Dave