I just now read this (and had cleaned out my inbox several hours ago), sorry
This would be hard to this make fit into an FMJ vehicle. It can be done but cost vs. benefit just wouldn’t be there.
A month ago, I just paid $225.00 (plus freight) for a ’68 B-body 8¾” housing and axles (no carrier/gears, though).
I'd highly recommend selling the carrier/gears separate from the housing/axle shafts. Everyone wants the 742 and 489 cases – but for most of us, the 741 is a very stout carrier. I can’t comment on the price for the carrier (I’ve a half dozen carriers in my garage for last 30+ years – so had no need to price any).
As for the housing and axles, I recommend creating an account at FABO
For A Bodies Only Mopar Forum and selling it there. This is a common and sought-after item for newer A-bodies or those wanting to get rid of their 7¼” differential (imagine that). If it is from an A-body, then it will fit into any A-body - but there might be an issue with older 5x4" vs. newer 5x4.5" bolt pattern wheels.
The carrier/gears can be sold most anywhere – for it will fit into ANY 8¾” differential (except for the front diff’s on 4*4 pickups). The downside is the gear ratio (2.76 – not popular) and being an open carrier.
For carrier/gear pricing, I would go to FABO (or FBBO, FCBO or FEBO) and look in the “for sale” section. Sense you will be new there, I wouldn’t expect anyone there to pay the "I’m going to get rich" price there. The “going price” or the “get rid of it soon” price would be what I would look for.
The housing and axles can be shipped via FedEx without too much effort. The carrier or complete axle – NO. The complete axle would need to be placed on a pallet and shipped via truck.
The carrier can be a bit fun to ship because it’s so heavy and I don’t have any recommendations on shipping one.
There is a good likelihood the carrier (and/or housing/axles) can be sold locally via Craigslist (maybe) – but I think you would get a better price/quicker sale on FABO.
Hopefully this helps
BudW