Can you please clarify: Did you replace both the coil spring
and shock absorber? Did you put in new ones? How much lower
is the left side? What is the condition of the the lower
control arm bushing? Inspect it under load and not under
load. How confident are you that the left front lower ball
joint is in good repair?

The other day I swapped the coil springs in the front for my
91 Civic. That reduced a difference of 3/4" to a difference
of 1/4", with the left being lower. This was consistent with
my springs' (fully removed and relaxed) heights: The left
side had been lower by 1/4".

I expect old bushings explain the remaining 1/4" difference.

From my googling, the left side being lower is very common
on c. 1990 Civics. It's not ideal.

I also discovered severely worn sway bar bushings and links
(on the right) that I think contributed to a tire wear
problem on the right front.

I have ordered (from "Team Honda" in Colorado) new springs
and sway bar bushings and links. The bushings will have to
wait until I have a bit  more  money and time.