I specify the R6 shocks and bellcranks for use with my mid-engined La Bala kit car that can be built from plans. I've put over 15K miles on my own 1,500lb car using 2005 shocks with 2002 springs at the front and the 2005 springs at the rear. The suspension works very well and the ride is incredibly supple. I spent some (expensive) time with my suspension guru testing a number of them on a Penske shock dyno throughout their range of adjustment. I also tested all of the springs on a digital compression rig designed to test spring rates. The results were enlightening.
I posted my findings on my website: http://www.grabercars.com/phpbb2/viewtopic.php?t=1865
Benny toe, looking at your photograph above; the effective rate of your spring will rise quickly if the bellcrank pivot bearing is binding and I think that one will. The bellcrank may rotate freely when unloaded, but it's amazing how the weight of the car plus the bump load will cause that pivot to bind up. My original 1/2" bronze bushings were too small and wore out after about 10K miles. I think you should consider fitting a larger bearing like this one in the photo. It's only a couple of bucks per corner for the oilite bronze bushings and some DOM tubing, plus some effort to get the pieces to slip fit nicely.
