When you read Hyperco's, you're reading about a Special Production for SR20Forum, just 70sets were maded, they're not a "regular" production.
If you want a good set of springs, get Tein's Springs & match with AGX's, by the way, the better setups are:
2front/4rear or 3front/6rear
This is the translation of the KYB table in real percent vs. stock
