69 Mustang Granada Disc Brake Swap Problems

So I'm new to the site, more of a guest really as I don't own a Ford (mopar guy actually, please don't shun me as I'm here trying to help a friend with his car). So I found a Co worker of mine brake spindle, calipers, and rotors from a 75-79 Granada while searching for disc brakes for my valiant. With a little research I fig they would be great on dans 69 and for $100 a steal. We replaced every thing and cleaned the spindles. We used 73 mustang outer tie rods. Since the Granada was long gone I couldn't get the proportioning valve and mc. We used a new mc from a 73 maverick for manual disc brakes and used the rod from the mustang mc. The new maverick rod was 1" longer. I was reading any Ford proportioning valve from a rear wheel drive disc front drum rear car should work. We used one from a early fox body mustang and then bleed the system real well. Now his peddle is rather soft not spongy like air in the system but soft like power brakes. But the thing I really don't like or get is he can't get his brakes to lock up at all. He said the brakes are a vast improvement but I'm not satisfied with them yet and don't want to see him or his classic car in an accident. Now I'm thinking its something with the fox body proportioning valve but before I start throwing any part or cash at this I was hoping for a little insight. Thank you.

The bleader screws on the calipers are pointed to the rear and the hoses towards the front. I have the rear of the mc going to the front top of the prop valve. The front of the prop valve with the removable fitting going to the front dr side. And bottom going to the passenger front. And front of the mc is going to the rear of the prop valve.

I had that thought but thought the maverick mc had it. Is there a better mc to use from a different year and model of car that has the valve built in. If so I will have Dan take that mc back and get a different one. If not I will get the summit one and mount it straight off the prop valve.

We had the car about level on 4 Jack stands when bleeding. Ill give it another try with the rear higher after putting in a residual pressure valve. So he needs a 10 psi valve only for the rear?

Bought the residual pressure valve and going to do a complete inspection on the rear brakes. Thank you horse for your fast input and assistance. Hope we have no more problems.

So I added the residual pressure valve after the proportioning valve, readjusted the rear shoes for a better fit and bled the brakes again. He said the peddle is higher and gets firm half way down. I held the peddle down around the half way point and it didn't move and maintained pressure. I had him run it on Jack stands to test the rear and had no hang up. Thank you again horse.