Wow - yeah, that's a lot. In general, my 1987 stock ride height was about 15.5 inches from the center of the wheel to the bottom of the fender lip, front and rear, with a full tank of fuel. With an empty tank, the rear is about a half-inch higher. Measure front & rear (take average of left+right) and see just how far off it is.

Remember, to change the pads/shims you have to pull the springs, which requires a Mercedes-specific coil spring compressor - it's not a DIY job without the compressor.