I'm in the middle of re-pipe of my house from the single story attic (slab foundation), and would like to come down an interior wall with stubouts for a future water softener. Right now I'll just solder in a closed loop until a few months down the road when I'm ready for the softener. So.. does anyone know the center distance of the inlets on one of the threaded bypass valves that slide into the back of the Fleck unit?

Thanks.