No response in brake section, sorry. Quick question!

Quick question about (metering / holdback valve) for front brakes.
Just converted a 66 Barracuda front brakes to disc from 73 Duster.
-Fwd / small chamber to rear brakes with adjustable proportioning valve.
I'm ready to plumb the front brakes from rear/large chamber of master cyl and was going to just use a tee fiting to route to the fronts. Is a metering valve neccesary or just a upgrade.
Also, does it matter how far the proportioning valve is located from master cyl.
Thanks.