The S/S springs are an effective way to help control axle wrap up and provide you with the ability your looking for in drag racing.
S/S springs have been used in some pretty quick cars. A buddy of mine ran high 9's in a big block all steel (except hood) Dart with those springs.
While currently, there are more effective methods (for the rear end) to run that quick, a lot depends on the cars actual weight, balance, set up and power. As to when the limit of the springs occur.