Found this. Don't know if it will help anyone.
Thought it was nifty.
Go down the page, fill in the blanks, and it will tell you what spring rate to use.
http://www.ridetech.com/tech/spring-rate-calculator/
Thought it was nifty.

Go down the page, fill in the blanks, and it will tell you what spring rate to use.
http://www.ridetech.com/tech/spring-rate-calculator/