SP009:
SP011 Front Springs (165lb/in)
SP012 Rear Springs (160lb/in)
SP068:
SP069 Front Springs (150lb/in)
SP012 - Same as SP009
The only reason I decided to come up with the SP068 Kit, is so that people would stop calling our SP009 "Drag Springs" - as that is what was happening due to how well they worked.
To be honest - if Bill has our older SP009's...he may have the dual rate design that is actually as good or better than any other spring out there (drag)....because upon the front settling, it transitions smoother than a true Linear design. I have an 8.5" tire car going 1.2, almost 1.1's with those SP011 Fronts (older style) that I found used for him, on purpose, when he came to me to support his suspension set-up.
If the car is inconsistent, I would try and work the geometry and dampers a little more to find the general spot where it works best on an average day.
I agree that the ARB will help out, based on pics and vids I have seen of the car.
Keep up the great work.