Are these variable rate or only HD?

[erasedhammer]

I noticed that I have the cast upper perches and when I've had 2500 lbs of gravel in the back the springs didn't budge.

Do I have the normal 3000 lb HD springs or variable rate?
They seem extremely stiff and I want to have the normal HD ones so I can upgrade to variable rate for the softer ride.

 

[gimpyrobb]

Since there is thicker rings and thinner rings, I would say variable, but I don't play with these trucks so I may be wrong.