Shocking Discovery!

huh - never had one come loose.. there's what - 6 spot welds holding it to the frame?

Yes there are but not towards the top of the bracket.
A nice upside down U welded over the tops of the bracket and to the frame rail solves it once and for all.
Some even run a tube from the firewall up inside the fender across the top of the top of the bracket and on down to the frame rail.

Here's a couple of the solutions.
In the second picture I would do it like the red lines because it would be a lot stronger.

1.jpg

2.jpg