hopefully you guys know what im talking about. my car was missing them, i blew the opti, put a new one on, all is good however my vent lines aren't secured to the little dicks coming off the opti for the vent lines, they are just chilling there and i have a feeling they are gonna come off. one is bigger than the other, i know that. perhaps GM part number.....?

 

GM does not list a part for the clamps only. They only sell the complete vacuum harness. You might find something suitable in the "Help" section of various items at some auto parts stores.