Uneven Ride Height Questions

I know this thread is old, but does the 2002 Mustang GT have the same problem too?

I recently changed my shocks and struts to Bilsteins HD and i noticed that only my rear driver side corner sags by about 1.5 -2inches. Yes, this was measured on even ground and by two mechanics from two auto services.

Please tell me if this is normal.

My Mustang:
-Stock springs.
-no accidents.
-the two corners in the front are sitting equal height.
-Tire pressure front and back kepted at 32psi and checked weekly (last check after struts and shocks were installed).