Coilover Spring Rates

[pwmin]

I have Rev9 coilovers on my 2001 GT.  I have 0 pre-load, which helps, but they're still a little bouncy and harsh no matter what I set the damper setting to.   I have ZZP coilovers on the red car and, while not perfect, they are much better. I'm trying to figure out what spring rate they are or if anyone knows what I should swap them out for? I'm also going to grab more collars so I can lock them together.  They keep coming loose.  They have a thin lock washer, but one of them broke.

[55trucker]

Hmmmmmm.......... the Rev9 supplier doesn't disclose the coil spring rates to the customer?

is it safe to assume you're using the 97-04 Buick Regal coils?

https://coiloverkits.com/collections/rev9-coilovers/products/buick-regal-coilovers-1997-2004-rev9-hyper-street-ii-32-way-adjustable