I have a '66 I'd like to convert to power brakes. A few questions:
What changes in the lines will I have to make?
Why is it so hard to find a master cylinder for a '66?
Would it be easier to use a setup from a '65 or a '67?
I did the conversion to a 66 using a 67 system with power booster.
Don't know what the issues are with availability of 65 and 66 systems but the dual cylinder on the 67 seems a good safety factor to me. Master culinders seldon just "Fail" but I had a line break once on a college car , read that junker, with a one chamber master cylinder. It was while I was on a hill and it was not pretty although I escaped w/o injury or accident.
Anyway as to your question about lines. I have to think here because this was done awhile ago.
The line that runs under the front crossmember can be retained, the long line from front to rear has to be changed. This one is a stinker and some folks say ya gotta remove the body. I did not remove the body..repeat I did not remove or lift the body. The new line is not dead nuts in the factory location but I was not about to life the body up. I think I made a slightly different configuration clamp(s) to attach the line to the frame. The issue is that you have a hell of a time with the bolts that hold the line to the frame in the original location if the body is still installed. I guess the important point is you can do this w/o removing / lifting the body. It won't be factory perfect but like I said..not about to lift the body
You need the later model distribution block for up front...it is required because it separates the circuits ofr the front and the rear brakes. and you need all the lines out of the master cyl. to the distrib block for whatever system you choose to use. The 67 setup I had had all the lines I needed and everything just fit into place.
In the back you can replace the lines if you want to, I did because mine were very old...original to the car. If I recall right it is not necessary though.
I don't think I have covered every little item necessary to do this. It was a long time ago when I did the job and the car is not currently garaged here so can't just look at what I did.
Also ..........I just remembered... you need to change the position of the shaft that goes from the brake pedal into the master cylinder / booster. The non power single chamber master cyls and the power, dual chamber 67 cyls use different locating holes for the shaft.