Factory ride height is measured off the lower control arm. The measurement from the to the floor to the surface of the t-bar socket should be 1.38-1.75" higher than the measurement from the floor to the lower ball joint surface (I forget which dimension it is exactly). But, if your still working on the car, adding parts and so on, this is going to continue to change. Setting the ride height should be the last thing you do before getting an alignment.
