I got a knock-off corvette style master cylinder that came in a power brake conversion kit. i don't know if it has the pressure valve built into it. It looks just like the stock manual corvette master that i had got from the flaps. The only diffference is that the kit master has a spacer that fills up the space inside the master were the manual brake rod would go. It works just right with the booster that comes in the kit. I can only guess that it has it. How can you tell?
