Does this new valve replace the old proportioning valve mounted on the frame and the metering valve on the master?
How important is originality to you? I bought a rear disc brake set up and got a Disc/Disc Proportioning Valve (D/DPValve. The new D/DPValve is somewhat different from the factory Combination Valve (CValve) since it adds a necessary proportioning aspect to the brake system to prevent premature lock up of the rear brakes
) The D/DPValve looks almost identical to the factory CValve that mounted to the frame, so I mounted the new D/DPValve in place of the old CValve (I got frame bracket from InLine Tube to facilitate the mounting
). The result is no one knows the Brake setup has been altered, because the D/DPValve is "hidden."
IMHO I think it looks much better to have the PValve on the frame than having the D/DPValve up by the M/S.
If originality is of no concern you can mount your new PValve up by the Master Cylinder. However, I believe that additional brake lines will be needed to do so...
So, I'd answer your question with "Yes."