1932 Ford Heavy front axle

Can someone tell me what the difference is between a 32 ford "heavy axle" and a non heavy one. Also is it different from a 1934 ford 1/2 to pickup front axle?

 

hard to describe , picture is better:

 

The 32 heavy has a slight variance where the bones mount, The axle is taller except for right there.

 

Check the area at the spring perch hole. A 32 axle has a recess for the radius rod because it is so heavy. It almost looks like it was milled down for the radius rod to slip over. The other axles have raised areas there where the spring perch goes through. Once you notice that you can tell from 10 feet away. The secret is knowing what to look for.