I have a 66 Cutlass that originally had a single bowl master cylinder with a booster. I'm not sure how many inches of vacuum my engine will pull so I'm leaning toward a manual dual bowl master cylinder set up with a proportioning valve for front to rear bias using disc brakes at each corner.
What advice can anyone offer about this swap? What if any pitfalls are there? Installation concerns etc. that I should be aware of?

Thanks for the help, G

After market Wilwood

You can run a manual small piston master cyl with large piston calipers for a good feel.
Proportion valve on the rear.
Almost as power brake feel.

The only thing the brakes care about is the piston diameter. If you want the Wilwood bling, go for it. Otherwise, a factory replacement M/C works exactly the same. All that matters is the piston diameter. M/C bolts to the top two bolts that held the booster. Run nuts down on the other two to retain the pedal assembly to the firewall. Connect the M/C pushrod to the top hole on the brake pedal. Done. This is not difficult.

My '67 442 uses a Wilwood adjustable proportioning valve mounted along side of MC to control front/rear brake bias. MC is a corvette style with a 1 inch bore. Front brake setup is '79 to '81 camaro/firebird disk and rear brakes are original drum for '59 9.3 inch Olds rear end. Even with the straight front axle, braking works well once brake bias is dialed in.

67 Olds 442 Gasser

I have the same set up it seems on my 66. Master for a C3 corvette with four wheel manual disk and a wilwood adjustable proportioning valve. Brakes are just one of those generic a body kits

Good stuff, thank you all.

Be sure to get and use the derby hat pushrod retainer.
Inline tube reproduces it, #12439