Adding Power Brakes

[HPCOBRA]

I have a CR big block with 4 wheel disc brakes from a 87 Corvette. The car was built back in 94 and has been in storage ever since. The builder put in manual brakes. It takes a lot of leg power to stop it! The brake system was new and supplied by ECI out of Vernon CT. The car has only been driven 75 miles since its build. I spoke with ECI and they noted that the brake configuration needs over 1000 PSI at the wheel cylinders and with the manual master cylinder in place it is difficult to achieve. They offer a manual booster that will fit the small area, but it is expensive. I heard from a reliable builder in California to use the 89-94 GEO Metro Power brake master and booster. It is small and will fit the area. Has anybody else had experience with this? It has a 13/16 bore. The Geo tracker cylinder has a 7/8 bore which would deliver more oil to the cylinders, but the pressure would drop by almost 200 PSI for the same leg effort. Any feed back would be great.
Thanks