All 8 rear bushings are the same.
I'd rebuild the old ones. Etch them with phosphoric acid (sold to clean up tile), rub them with scotch brite, spray them flat black rustoleum. If your car is for the streets, I don't see how you'd benefit from boxed LCAs.
BTW, I have a set of upper/lowers rebuilt and painted with new rubber bushings, but wouldn't sell them for $200 because the shipping would probably be $50. They're prolly going in the Cutlass this summer. Once you get them out of the car, it is a couple hours of easy work.