Can't get good brakes
I have been ill since April but able to get into my 67 GTO last week. What was wrong is not important. I installed an SSBC front disc brake conversion kit with new master and vacuum assist. With that I used a CPP model PV-2 two disc proportion valve so the front discs and rear drums work correctly. Everything was installed to the book. Master bench bled and I had to first gravity bleed the front and rears then bled them with someone on the pedal. I have a great pedal inside the car but it stops like crap. If I am going back and forth on my driveway, all is good. I took the car down my street and it slows down then stops. Not safe. I am at wits end. I called the makers and they tell me I didn't bleed the master when I did. I even used a Motive pressure bleeder, no bubbles in any wheels. I have done in my past, easily 100 brake systems. But never a conversion. Always stock swap outs. Anyone out there have experience with this? I am almost stumped. It makes no sense having pedal pressure, no air bubbles but not stopping like discs should.