Yes, I have stock suspension, Thornton suspension and I also manufactured my own springs which I currently use for the Girdraulics. I made a clamp to hold the rear boxes, but ultimately, I found the carpenter clamps easier to use. About a decade ago I made a coil over unit for my rear suspension using a Thornton damper (which Thornton now sells) and I use that. I had problems with the inner spring boxes wearing through the outer spring boxes and creating stiction points. I also had a spring box "cock" as a result of the stiction. That is why I moved away from spring boxes.
David