Brake Questions - Help

That is great information, not ONLY Is it a 340HO 4 speed, but has a large cam in it (still flat tappet lifters I think), a 750 Edelbrock 4 barrel, AND fender well headers (yeah I said it). So the car needs the brakes to work right. To round it out, it is 1 of 52 of these types of cars they made in 1969 (low production number) so I need it NOT smashed. And I need to custom bend the lines from the MC to the distribution block to got back to the firewall then down and forward to miss the headers. Kinda crazy. Finally, it is a factory power convertible.
Seems to me you might want to take a look at the fender tag and see how much info is on it. Shop manual will have some basic decoding. Some of the guys here will be helpful, especially if you are putting some effort in on your end. In addition to the imperial club, another great resource is The 1970 Hamtramck Registry Home Page

List of master tech bulletins and filmstrips:
Master Technician Service Conference - Chrysler's Training for Mechanics

here's direct to a picture of the combo valve:
1970 Chrysler Imperial Hydraulic Brake Service Guide from the Master Technicians Service Conference Session 274
1970 gets confusing with all the variations, even though the concepts remain the same. That's why I didn't want to post that earlier when it seemed likely the disks were a factory option.