I don't know for sure, but I would guess they would be different.
At the very least, the weight distribution difference with the iron block and supercharger on the front end of the 2003 would change the amount the car would drop when compared to the 2001.
In addition, when I bought springs, I tried to keep the spring rates as close to the stock springs as possible. My reasoning was to have the best chance of utilizing the design-matched bilstien shock damping chosen for the car by SVT.
With the Steeda springs , the car maintains good ride quality while gaining an aggressive, low stance.
Spoke to Steeda. They are developing a set of springs for the '03. The 99-01 springs were not designed with the optimal spring rates for use on the 03.