So... to be clear: the complete drum brake package (from backing plates outward) from any 1973 and later 7.25, 8.25, or 8.75 can be transferred to another 1973 and later rear end?
If the 7.25 is the large bolt pattern, yes. In A bodies, they produced both concurrently '73-'76, small pattern w/frt. drums & large pattern w/frt. discs.