Speaking in general terms..

If any shock is subjected to a load that makes the piston rod smack into the bottom of the shock body - a situation more commonly referred to as "bottoming out" - then you're going to bend or break expensive suspension parts. Worst case scenario, you could crack the oilpan like a raw egg.

If the car is scraping a whole bunch at - 2", why would anyone want to go lower? h:

My 2.3¥