Help Required With Coilovers

[R-SPEC]

Hi

im a noob when it comes to suspension which is why im asking

i've got a pair of rear r34 height adjustable coilovers, how do i go about finding out what the spring rate is? brand is "DEED" and they have no tags etc on them. on the springs it says "deed 050"

im asking because i wanna get a pair for the front aswell and just need to know what will work best with these rears

thank you

[R-SPEC]

never mind found the page