Brake guidance for 73 with power disc brakes

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May 1, 2021
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I'm in the process of bringing my 73 mach1 back to life.  It has power brakes, discs up front and drums in the rear.  The brake system is somewhat pieced together and I suspect its not entirely correct.

The master cylinder has a power brake booster and 2 pools under the lid and 2 outlets.  The front pool is smaller and the rear pool is about 3-4x larger capacity.  The front outlet is threaded 1/2-20 and the rear outlet is 7/16-24.

My proportioning valve, I'm pretty sure was pulled from a 72 mustang with 4 wheel drums.  It has a 1/2-20 inlet which I believe feeds 1 line going back to the back of the car.  It has a 7/16-24 inlet, which I believe is feeding 2 lines, one to each front wheel.

Does this proportioning valve sound like a correct part for front disc and rear drum setup?  

Which outlets from the master cylinder connect to which inlets on the proportioning valve?  I have the parts here to make lines connecting the two.  Just want to double check that I connect the correct stuff.

If I decide down the road to install some aftermarket rear brakes, are the disc/drum proportioning valve and hard lines good to go or do you have to run a different valve and/or new lines?

My proportioning valve looks like this one

What's got me scratching my head is the way its oriented in the car, on that proportioning valve, the front brake connections are on the front and the rear brake connections are closer to the firewall.  However, I was under the impression that on the master cylinder, the pool and fitting closer to the firewall was the front brakes.  It just seemed odd to have to cross the lines coming from the master cylinder to the proportioning valve.

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Jan 1, 2012
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Eugene, OR
My Car
1971 Mustang Sportroof M code