actually.
spring rate has very little to do with height.
spring length does.

sure, if you put 500lb. springs in a car that should have 1000lb. it will be lower, but the springs will also be preloaded and have higher effective rate.
what you need to do, is figure out the height you need. then rate. and order custom springs.

and its not that i dont understand english, its that youre going about this incorrectly, and going way overboard.
hardbody with 240 suspension?
why, who cares?