That part # shows up as fitting the C3500HD, disc/disc P30 chassis vehicles, & one specific subset of Tahoes & Cadillacs. Finding one will be the trick. Might be in someone's new old stock inventory, or have to find in a boneyard.
Quick search. Maybe better pricing elsewhere?
For used I would do a parts locator search on p30s, problem is - did some mechanic swap it for something before.