sway bar and rear control arms

[Derek69SS]

That's correct John.

65-70 Impala used the exact same rear swaybar as a Chevelles. GM still sold the rear bars new a few years ago for ~ $120, but I think they may have been recently discontinued... they might still have some in stock though.

Later cars mounted it differently, to the bottom of the rear arms instead of to the side. With some creativity, you could figure out how to adapt it to Chevelle arms. I've never tried it though.