On 2 different cars, i added extra leaves into the rear springs. The more you add, the more it lifts the car. Additional to the leaves, you need to use longer u-bolts and centering bolts. The cars immediately sat much higher, then over several months, settled. With the top up, they are slightly higher in rear than front, top down they ride level. I try not to use air shocks as they move the load from the spring shackles to the shock mounts. Hope this helps.
Bill