68 Cougar hard pedal brake issues

New Master Cylinder
New Power Booster
New fluid
No leaks
New Proportioning Valve
New Front Rotors
New Calipers
New Front Flex Lines
Electric Vacuum Motor

Just had all this installed and no power assist and pedal is very hard. Appreciate anyone’s advice.

Typically the booster rebuild is done in some third world country and it is typically a Bendix single diaphragm booster that does not have as much boost as your original booster which would be a Midland dual diaphragm. The Bendix booster can work OK if the timing is set properly so you have a lot of vacuum.

What is your timing set to? How many inches of vacuum do you have?