spring rate on 4" springs

[jmwright111]

does anyone know the spring rate of some of the common 4 inch lift coils.
i found rough country and tuff country but i can't find any measurements or ppi.
anyone have either of these and can say how they perform?

 

[jmwright111]

ok i found out the rough country are 434 ppi for the 4" lift ones for ranger and explorer anyone know about tuff country or skyjacker?
i found somewhere the skyjacker ones are something like 400 ppi not sure if that's accurate but probably is

 

[4x4junkie]

Skyjacker 4" coils are in the neighborhood of 470PPI.
Skyjacker 6" coils are lower, around 410PPI.

Superlift 4" coils are around 530PPI (yeah, might as well just use a piece of solid pipe instead of wasting $$$ on these )

I have Skyjacker 6" Cherokee coils (pt# JC60F) on my BII. They are closer to 240PPI and actually work FAR better than anything that's specifically made for our trucks.