Dandan
I spoke with my brother. He says the Alfa Romeo Milano guys in the SCCA did "bake" their springs with a spring compressor on them to "age" the spring, lowering them. They did this with absolutely stock springs so they could run the car in the stock class while Auto-crossing.
This being said, I was lead to believe, different spring manufacturers offer a small variety of the rubber pads that sit at the top of the mount. Maybe a thinner/stiffer one is available which will gain you a few mm.
