From my experience of installing various aftermarket suspensions on different car makes, the measurements will always be off at first. You need to drive the car for a few miles on freeway, street, and some turns. I would say about 50 miles total. Then go back and measure. Everything should be seated by then. Seeing how the suspension you installed are not adjustable coilovers, you won't be able to adjust ride height for fine tuning. All you can do is check to see if the springs are seated correctly on their perches. If everything else is nice and tight, that might be the way the car stays. One more thing, check that all air pressures on the tires are matching. You never know, a few more pounds of air could throw your measurements off.