What you probably have is a Mustang rack, for power steering. That has a ratio of 15:1 , IIRC.
I use a Flaming River rack, 15:1; which is considered a quick ratio. I find it to be just about perfect for what I do. Steering is very responsive, but not in the least bit scary. FR also makes a rack that is a standard 20:1, which is probably more of what you want.
http://www.flamingriver.com/index.cf...prod/prd41.htm
But keep in mind this is a sports car. It's supposed to be very responsive. Not as much as you describes; I agree this is a problem. But even with a higher ratio rack, it will turn very sharply.
I would take a close look at these parts from Breeze automotive. Might be just what you need.
http://www.breezeautomotive.com/deta...=364&cat_id=12
http://www.breezeautomotive.com/deta...=485&cat_id=12
http://www.breezeautomotive.com/home.php?cat_id=12