Need some Suspension Advice Please....
Let us know what you find out.
Btw, is this a new problem or has the car worked ok until the most recent outing? 50/50 for a rear setting is ok. Stiffer, like 7-8 on a rancho also a good place to start.
The spring clamping is also a good recommendation so you can change the spring frequency. Adding a little weight to the front will do the same.
Good luck.