If the parts you're referring to are bullet-shaped rubber pieces with a nut inside that expands when a screw is tightened into it, you've got mounting grommets for the regulator used with the "Delcotron" alternator- - - -the first-generation alternator system before the 10-SI internal regulated alternator came into being. They could be used with a DC regulator for extra vibration protection, but they're not necessary since the DC regulator already has vibration isolator grommets.
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!