67 SS427 Impala R/Spring Advise?

[ss427copo]

Just getting around to figuring-out the 3/4" ride height difference from the lower, driver side vs.the higher passenger side (both at the front & rear, even though the front is a tad bit less), measured from ground to mid-line of wheel opening) on my Impala.

Frame has never been off, front end rebuilt in 84 yet rides like a dream. Has F41 suspension. Thought about doing the rear springs to see what that does?? Any advise on this step and maybe where to buy the springs that would be correct .

Jeff x2