Choosing a rear suspension
IIRC, even in the MoPar books, getting into the 9’s, they recommended something else besides the SS springs. IIRC, 4 link came to mind. These writings are before. Al Tracks or Assassin bars came out.
I have a few buddies (in the past) run high 9’s on S/S springs. Over powering the spring is easy on 13 second cars if nothing else is addressed. SS springs aren’t magic springs. Just part of the equation.
How heavy is the car?
Car Weight Distribution is????
Over all weight?
Are the rear clamps still holding the springs together?
Are the front clamped?
Extra clamps?
How much tire do you have?
Did you make sure the rear shackle is properly placed allowing movement properly?
You can also use sliders in there place. (Shackles)
SHOCKS!!! A major roll ignored.
How hard is your hit?
This is also a problem no matter what set up you have. I say this because the best OOTB set ups aren’t looked at, just installed and raced. I know if you guys that have opened up the box, installed the part, went racing. And then they wonder why they did I wheel stand, why didn’t I wheel stand, why do I go right/left, they get swirly down the other end, etc....I myself would use the assassins and a split mono weeks for the cars weight. If you’re moving away from that, then you might want to look into something a bit more exotic than SS springs.
Like a 4 link.
Have fun and good luck!