See AIM Page 223, under RPO C60 (AC), View B. The clip, PN #3825416 is clearly show and there are no notes in the revision block that states that GM deleted the clip from production. If some reason the clip was no longer needed, I would have suspected the AIM would have had a revision note stating clip had been deleted during the production year. Granted, this is for an AC car...
I'm still searching the AIM, but so far, that's the only place I see it referenced. Interesting, no where on Page 44 under heater hoses is the clip mentioned - not even in the revision notes stating it's been deleted.