After 4 years I think I finally found my problem.

[thrashingcows]

Ahh I see thank you for the clarification...I actually would have thought the piston and seals would have been different but clearly Ma Mopar decided to save money on those parts and make them the same between the B/C/E body lines and just have two different castings.

 

[Zymurgy]

Well Goldie's brakes passed in flying colors, on the trip to Nats today, 120+ miles. I still had some wheel vibration on my 10 year old Coopers, so new tires are on the list.

I am going to change the wheels to the 17" alloy American Racing V501 "magnum 500" style. Now I will have many tires to choose from.

 

[Ross Wooldridge]

Hooray! Glad to hear of this success!

 

[John Kirby]

I did this conversion on my 66 new yorker about 35 years ago. Grabbed all the parts off a 72 Newport. Worked very well. It would lock up the brakes when i stomped on the pedal.

Now it's a different story, after the years long restoration the brakes need the leg of hercules to stop the car. Replaced the rotors, calipers and master cylinder + prop valve. Not much help. During this time the old master cylinder puked into the booster and it was replaced. I then found out the booster was for a b-body so I obtained a 72 c-body version and had booster dewey rebuild it. That helped a lot but I still don't have the brake response of 35 years ago. I will look at the guide pins, don't remember if they were replaced. If that doesn't fix it I'm not sure what else it could be.

 

[Zymurgy]

I did this conversion on my 66 new yorker about 35 years ago. Grabbed all the parts off a 72 Newport. Worked very well. It would lock up the brakes when i stomped on the pedal.

Now it's a different story, after the years long restoration the brakes need the leg of hercules to stop the car. Replaced the rotors, calipers and master cylinder + prop valve. Not much help. During this time the old master cylinder puked into the booster and it was replaced. I then found out the booster was for a b-body so I obtained a 72 c-body version and had booster dewey rebuild it. That helped a lot but I still don't have the brake response of 35 years ago. I will look at the guide pins, don't remember if they were replaced. If that doesn't fix it I'm not sure what else it could be.

To me it sounds like you need to replace or rebuild the whole caliper. Mine would still stop on a dime with no effort, the pin problem was not release the caliper completely.