Need Help With Disc Brake Coversion

Hello to all. I need some advice regarding the brakes on my 1968 Dart. It originally came with power drum brakes. Somewhere along the line, a previous owner changed the bolt pattern to 4 1/2". At the same time, he swapped the front brakes for the 1970-1972 B/E body discs and 11" rear drums.
When I got the car, the brakes were pretty non-existent. First thing I did was ask you FABO folks to identify the calipers. That's how I know what they are. Next, I asked which M/C to use as the car still had a drum M/C (same size reservoirs). It was recommended that I swap to a 70-74 B/E body M/C with the 1 1/32" bore(new Bendix). That made sense as it matched the calipers so I did this.
Brakes were still lousy so I swapped the calipers with NAPA rebuilds and new front hoses.
It was also suggested that I install a delay valve in the rear line as per factory disc cars so I did this as well.
Now here is what I have: the braking is very poor and only the rears seem to be working. If I close off the rear brake line, I am barely able to stop.
I am using the Dart booster. According to NAPA, their booster works for 1968-1972 Darts. Though I am using the "B/E" master, shouldn't this still work?
I'm open to all suggestions.
Here are my questions/thoughts: could the brake distribution/junction be a problem? I don't think this was changed.
Can you use the same distribution block for drum and disc brakes?
Do I need to swap the distribution block for a "B" body one as this is where the brakes come from?
Author: admin