I have ONE brand new Koni yellow (racing) shock pn 80-1997Sport for the rear of a GT. It was sent to me by mistake by a European vendor and shipping is too expensive to return.

They are not only designed for stiff springs, they are designed specifically for a lower ride height. These shocks are shorter than OEM.The yellows are even more radical and work best with REALLY STIFF springs.
Fine for a track car.