Ok .. Doctor Diff looks like the way to go. I am currently working with manual brakes. Do I have to switch to power brakes or is my manual master still ok. And would it benefit in any way to do the 11.75 inch Kit.
You don't have to switch to manual brakes, but you should replace your master cylinder because it's a drum/drum master cylinder. I use 15/16" bore manual master cylinders on my cars, they give a little more pedal travel than stock so not as hard of a pedal to deal with. Plus the little bit of additional travel improves pedal feel and brake control, at least in my opinion.
There is a benefit to the 11.75" kit, more stopping power and better heat dissipation. They're still all stock parts too, used on the later B and R bodies. I've had them on my Challenger for like 70k miles, they work well and are a nice upgrade over the 10.95's. The do require 15" wheels though, 14's won't work so if you have 14" wheels that's definitely a consideration.
