This may have been posted before, but I thought it may be interesting to some if it hasn't been. I was going through some paper work I have for my GVR-4 and came across some specs for the Whiteline springs I purchased back in 2001.
Fronts are Whiteline part # 80442
Rears are Whiteline part # 80443
Those spring rates are probably a little light for our heavy cars, but don't work too bad with the semi-soft valving of the AGX struts.