>>4637053If you've got a site that sells springs, I bet they have a sales rep you could talk to that could recommend a rate based on your dampers, vehicle, and intended application. Or, if the sales rep can't help, you KNOW there's some engineer in the back room that'd just wet his panties to figure it out for you.
I'd recommend at the very least figuring out what the stock spring rate is, and probably talking to Bilstein to see what spring rates they recommend for your dampers.