Technical How to tell the difference from a Model A rear end and a 40 Ford rear end...

So I've run across a few banjo rear ends here and there. And I think to myself "well how the heck do I know what I'm looking at". To me the 40 Ford and Model A rear ends look almost identical.
Can anyone help me out identifying these rear ends? Is there something to look for that makes it obvious to someone who knows what they're looking at? Or does it come down to taking down the serial numbers and going from there?

 

A mechnical brakes, 40 ford hydraulic. Gary

 

A's have spring hangers on top of the outer axle housings...

 

Model A has the spring mount over the top of the rear end, 40 is mounted behind the rear end, look up Hot rod works they have pictures that ID each change and year,

 

Thanks guys!

 

The flange where the torque tube bolts to the center section is round on a Model A and scolloped after late 1932.


Charlie Stephens