Help - No Rear Brakes On 94 Gt

I need some help. My 94 GT rear brakes do not work. So far I have installed new rear calipers, new brake fluid, new master cylinder and completely bled the entire system. I can jack the car up and put it in drive WITH brakes applied and back wheels still turn. Front brakes work great.

The car does have ABS and no warning lights or codes are present to indicate it is not functioning.

Anyone had similar experience or advice on what to do next?

I can bleed the rear brakes but when I bleed them there is not a lot of fluid discharged for each pedal push. I cracked the line before the proportioning valve and have great pressure and volume. I also cracked the line before the HCU and the volume and pressure is the same as I get at the rear after the HCU. I suspect it may have something to do with the proportioning valve. I have purchased a wilwood adjustable valve to replace the original proportioning block. Ill finish it up hopefully tonight after work. Fingers crossed as this has been really frustrating.