Classic/Antique Car Repair: no brake pedal, 1960 chevy belair, geo metro

Question
I just bought  a 1960 chevy belair with 305 engine and 700 r 4 tranny .The cart has 1970 nova  disc front brakes and a 1992 geo metro power booster and master cylinder .With the vacuum hooked up I have no pedal(goes right to the floor) .If I unhook the hose  on the 600 Holley then I have good pedal ? The resevoir is full/no air in lines /no leaks and brakes are adjusted good .Can you tell me how to trouble shoot this problem as I have tried everything my son and I know to do

Thanks In advance Bob

Answer
The first thing that comes to my mind is the size of the master cylinder bore. The metro bore is only about 3/4 of and inch while the Nova cylinder is over an inch. It is more than likely that the metro cylinder just does not displace enough fluid to activate the Nova discs plus what ever is on the rear of the car. Beyond that there could be a problem with the way the set up was installed, the proportioning valve, the pedal linkage, and more. But I would start by making sure that the master cylinder had enough capacity to fill the hydraulic lines and cause pressure.