I have not seen this anywhere. How can you convert a single cylinder 65 Cutlass with power brakes to a dual cylinder with proportioning valve. I don't want disc brakes the drums work fine. I would just feel safer when I'm in the mountains that if something popped I wouldn't loose everything.

 

Many places sell that set up. SSBC, Right Stuff, CPP, etc, etc.

 

There is no proportioning valve in a drum/drum system, just a distribution block with the differential pressure switch that lights the BRAKE lamp on the dash if you lose pressure in one side. The dual circuit M/C requires a different booster, or at least a shorter pushrod between the M/C and booster.

 

The thread below explains it a little more. The easiest way is to use a 67 booster & master cylinder.

https://classicoldsmobile.com/forums...ngle-dual.html

Hope this helps.

Don