Goot's got it.
If you have an existing shackle reversal and want a bolton solution for rear springs up front, our kit still install identical to having a shackle up front. Only instead of relocating the fixed end of the spring, you push your shackle back. The axle is not moved back though because of the relocation hardware in our kit.
You will sit a little higher when its done, but if you are SPUA, it will only be about 1/2".
If you are thinking of doing a S/R with rear springs and have not installed it yet, the warrior kit would allow rear spring installation by itself. The forward mounting system can be pushed fore or aft. To run rear springs with it, simply push the assembly forward before welding to the vehicle. The shackle would still remain in the same location on the original spring hanger.
Any other questions or if you need further clarification, please feel free to email back.