Don't believe you can install them upside down as the coil's diameters may differ from top to bottom. I think the upper spring perch is larger diameter, as it is the same diameter of the upper strut bearing...and the lower perch is more the diameter of the shock tube. I could be incorrect...and it doesn't matter one way or the other. Ride height would only be affected if the spring's coils sat differently on the lower perch when upside down.