Rear sway bar for 1964 plymouth valiant

i honestly can't say on SS springs. some say 1.5" some say 3"

anyway, i think that the waters muddied here going off on a tangent about spring rates and bars and balancing a system.

here's my take: the SS springs will work but they might not be optimal in ride quality, or handle to your expectations, they will more than likely be high enough in ride height to clear the tires. i would strongly discourage running a rear sway bar with them.

in the guise of use what you have, yeah, they'll do the job. i mean, nobody wants to drop coin on another set of something when you have it sitting there on the garage floor. you can put them in, see what shakes out. maybe they're exactly what you were looking for, maybe you hate them with the fury of 10,000 suns; but at least then you can make a more informed decision of what you actually want and the direction to take in order to get that.