Kamispeed is a company known to me. It looks like they are dealers for lots of
suspension stiffeners. Its worth following your link for people to read up on
what they offer other than Swift Springs.

Generally a spring's job is to support the weight of the car.
The very act of replacing springs and shocks will make your suspension work better than an old setup. I choose to use my original springs and heavier shocks for ride comfort and I use heavier anti-sway bars to keep the car flat in the turns. I also modified the stock springs to lower my car 3"......photographic proof available at the meets which I attend.

You might check your spring rates to see if they are close to stock. Springs that are much heavier than stock don't really gain you anything unless you are being pressed down into the pavement in a banked turn, or unless you are getting airborn and need heavy springs to keep you from bottoming out when you land. -Bob

Here is some further info on the role of shocks, springs and anti-sway bars:
https://www.tamparacing.com/forums/ch...sway-bars.html