I went with the 20% over SpeedStar spring in my '00...works great !
You got a part # Chromepony?
Not Chromepony,but here ya go directly from a Yami
SPD-4WM09-84-00 = 7% additonal clamping force
The spring rate is about 7% stiffer than the stock spring for 98 cu. in. engine to handle the increased power output from Stage III configuration. Fits '99-'03 Road Star models.
SPD-4WM09-84-10 = 25% additonal clamping force
The spring rate is about 25% stiffer than the stock spring to handle the increased power output from Stage IV configuration. Fits '99-'07Road Star models.