They're called "Pal-nuts", and they aren't original equipment. Pitch them into the nearest circular file and don't bother to reinstall them. They're used on 235 connecting rods in some applications, and they're also worthless there, although Chey did use them as OEM for some silly reason.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!