'78 body mounts

[BigV]

Hi, I am working on a 78 bronco with a 3" body lift. I do not like body lifts and am taking it off. I already got the body mount bushing but I need to get the body mount hardware. I found one on BroncoGraveYard.com

BroncoGraveYard

My question is this, on this page in the note it says: Note: first position (core support) upper sleeve not available. 8 upper sleeves 10 lower sleeves 10 bolts

What is this first position upper sleeve? and where can I get it?

Thanks for your help.