For posterity, since I wondered about the source of this noise for some time:
I was having some light clunking noises coming from the front end, only audible with the windows down at slow speeds. I lubed up my propeller shaft, checked my differentials, checked for various rattles around the truck, etc., and finally noticed the noise goes away when I hit the brakes. I had replaced my front brake pads some time back, but didn't get the hardware kit (rookie mistake). One of the anti-rattle springs was a bit rusty, and had managed to deform enough to contact the rotor and start wearing away, until it detached. I replaced the springs, and of course the noise is gone.

There's a bit of spring missing here.

 

I don't recognize the top spring and it looks like it had a factory design to it from what it appears to me even though it is broken. Not many from new York, Welcome to Yotatech. Been a while since I have done a front brake job so that may be a correct spring.

 

Thanks Terrys87, I've noticed the lack of quality wheeling out here

here's the replacement spring from Autozone: