If I'm correct mine is an early design with a bolt that screws into the socket, where I've seen many that are a nut and they screw onto the threaded control arm shaft, I know the early first year F cars had some design issues that were altered and from what I've read DeLorean had the front end changed from the Camaro right out of the gate to make it better, still, every car I've seen especially 68 and later has a different A arm and bushing set up than mine, my A arms are larger.
That's why I was holding back unscrewing it, it's a bolt not a nut on a shaft. But I guess you're right, the bushing should stay in place.
I also have fond memories of changing the front springs on my buddies 67 GTO in 1977 with a chain and floor jack.