FWIW - I have an '04 ZTS with the same '04 wheels & suspension kit installed.
I just re-measured the distance from tire to fender lip as you did in the pictures, and it matches exactly. 2" at the front, and 2.5" at the rear.
Hope that helps, it looks to me like the proper "new" ride height. The "drop" I got from stock suspension to SVT kit was about .5".