'97SS

Hi everyone. I picked up an adjustable ta from spohn and i'm wondering what I should set it up at. I have had some vibration at higher speeds since I lowered it a while back with an eibach pro kit. I've done some searching but cannot seem to find a specific angle (if different) for a lowered car. If I were to assume, the original angle just got lost due to the factory torque arm being non adjustable. Set it back up at -2? Thanks