I've found all of the numbermatching bigblock Mopar engine blocks from highdollar '69/'70 Mopars fit my fullsize Chryslers just fine and are even more fun to drive and abuse...
The larger B-body poly-urethane leafspring frontbushings fit '65 C-bodies just fine aswell. The smaller bushings fit earlier Chryslers just aswell. All poly shackle-bushings interchange aswell.
Same goes for poly-urethane strutrod bushings although the inner ones have to be ground down.