Who has Dr. Diff 8 3/4 rear discs? Pt. 2

I started a thread here, awhile back asking for help with my Dr. Diff rear brakes. I am still having the same problems, despite getting his parking brake cables and a factory parking brake lever, cable and equalizer.

So here is the issue... I have a 70 Dart with Dr. Diff rear disc brake kit with the mustang calipers, they have an integral parking brake (single piston applies the brakes and is used for the e-brake) I purchased his 15/16 master cylinder and his front disc kit along with his parking brake cables.

I re bench bled the master cylinder and the entire brake system, adjusted the parking brake cable, but still no matter what I do, with the car on jack stands in drive, the wheels won't completely stop, not with the parking brake applied or with the brakes applied. I am not sure what I am doing wrong.

Here is a video and also some pictures of my e brake cable routing and setup.

Thanks for any help, this is literally the last piece of the puzzle before I can drive it for the first time in about 8 years.