[ERA 626]

I am being told by a reliable source that to set the ride height correctly on a CSX car.

You need to set the lower control arms LEVEL!
This is easy to do for the front, but the rear however is the issue.

With the car up in the air (on the lift) when I snug up the spring only tight enough to make it not loose, then I put the car on the ground the car sits a little high... When I loosen the spring more it kind of seems too lose but the car sits lower, in order for me to get the car to sit lower to make the control arm even close to being level the spring is completely loose when the car is in the air, but when I lower the car and put weight on it it is good. Is this normal? am I missing something?