BU code 373 12 bolt rear end housing build date is 3/28/69 and casting date is c/26/9 is march 26th 1969 this 12 bolt housing was out of a z/28.
https://www.facebook.com/marketplace/item/754164414080758/?ref=browse_tab&referral_code=marketplace_top_picks&referral_story_type=top_picks
It could be from a Z28 or another car. Without proof it's just a story. Now if we had the VIN for the Z28 it would be more believable.
$2500 seems like a lot for bare housing that has been modified with C-Clip eliminators and what appear to be aftermarket axles.
It is in Holbrook, NY
Seller information - Jonathan Norwood Janice Norwood