I will not cut all the brake lines to install a adjustable proportioning valve with a rear pressure gauge, so this is my way to save the brake lines, front metering valve and switch.
What do you think.

Jerry

 

Care to explain the plumbing....How it works, etc?

 

If you look at the picture with the pens. The top pen is the port from the master cylinder and you can see the flow will be to the outside of the tube in the factory valve and go into the new aluminum body and out the number 4 stainless line to the inlet of the SSBC adjustable valve and then down the center of the o-ringed tube to the factory valves outlet. (the lower pen.)
The pressure gauge is tapped in on the downstream side of the new adjustable valve to see the rear brake pressure.

Jerry

 

Not sure if I understand it, since the external goes of of the adjuster & back into the adjuster, but only 1 inlet/outlet to the adjuster.

Is this something you have considered selling to others?