We used to run a screen between the hat and blower, that was back in the 6-71 days and you could by them off the self from anyone that carried GM parts.
It had fairly fine wire on about 3/16 (6 mesh) spacing. Over time that screen saved engine several times, as we found a variety of things caught by the screen, ie. rocks, nuts, trash, you name it, and yes SSS, the nuts were the metal type.
So; I found that a screen that would stop the big stuff helped, but any finer than what we had would have a very negative effect on air flow.
Rouse