hows my 67 mustang front/rear disc setup

[DCx]

I have a 67 mustang that was originally power front disc and rear drum. i have retained the front 4 piston discs and added a fox body 8.8 out back with sn95 discs. After reading through a bunch of mustang forums looks like everyone uses either a SVO mustang, sn95 cobra, or 2000 v6 mustang 1'' bore metric master cylinder with the 67 power booster. I planned on getting a v6 master from the junk yard and making my own metric bubble to double flare lines to plumb it into my stock distribution block with the addition of an adjustable prop valve for the rears.

Now my car is an early 67 and it has a brass residual pressure valve installed in the rear brake line just above the axle. do i need to replace this valve with a 10psi residual valve for the rear discs or would this defeat the purpose of the rear adjustable prop valve?

[MonzaRacer]

The residual pressure valve is to keep the pedal from being so low with rear drums, in some cases it will cause the disc brakes to drag. AND the old ones DO get cruddy. So swapping it for a regular union or short section of line to start THEN if you need any thing like that Wilwood makes them in 2 psi for disc and 10 for drum, but you can use either as needed to "dial in" the pedal feel. just make sure the calipers isnt dragging if you install one.