IMHO,yes save the whole thing,they dont make them any more
the axle are most likly canadates for a cut and respline,have a larger flange end with the 5 on 5 1/2"wbp so it can be redrilled for the 5 on 4 1/2" wbp
the housing is a good canadate to have narrowed also
spring perches are on top of axle tube,but are 43" centers same as an A-body(I have an A-body 8 3/4 in my truck,tucks 12" rims and 29x15x15 m/t right in there)
my 72 4x4 truck 8 3/4 had a 489 with a 3.91sg in it
I save every one I can get a hold of myself