HOW TO DESIGN A SUSPENSION SYSTEM
If the a-arms are only mounting at junctions between tubes, it seems like it would be stronger for the mounting brackets to have flat bottoms and be U-shaped, as opposed to having two tabs with round bottoms...
So this:
would probably be less strong than this:
in the context of these points:
upper a-arm aft
lower a-arm aft
upper a-arm fore
lower a-arm fore