Torsion Bar Recommendation

Everyone says the KYBs are "harsh" but I have never really noticed that — maybe I am just used to them after 25 years. My fastback, with stiffer springs and f & r swaybars is definitely more controlled, but also understeers, especially going downhill — really needs 80+ more HP to bring the rear end around, and that is with the same size tire on all 4. It is handicapped in the twisties by the super slow factory manual steering, although it gives good feel at high speeds. The convertible, with factory soft spring rates and front bar only, feels much more agile in low speed corners with the Borgeson power steering. I'd even say it's quicker through 20-35mph hairpins, despite (or because of) skinny tires. Also, in real world driving situations (Northern California back roads) it can maintain higher average speeds than stiffly sprung sports cars (TR6, 911) over badly-paved roads because of high ground clearance and the soft springs soaking up the bumps, while they have to slow down to keep their teeth and oil pans intact. There is a reason rally cars don't have super stiff springs — what they have is lots of suspension travel. Not preaching, just pointing out there are different approaches depending on how you use the car. Wheels and tires probably have more effect on handling than spring rates, and are easier to swap. But if you already have the tires you want, then it's time to look at the details.