There are too many variables to answer that question with any degree of certainty. Somebody with a good engineering background would need to know a lot more about wheel cylinder and disc caliper diameter, and the diameter and stroke of the master cylinder, available manifold vacuum, and a few other variables before any answer you get would be anything other than a S W A G- - - - -maybe even a W A G.
Of course, a few others who post here will be happy to pull a figure out of their nether regions with no supporting data whatsoever. That advice is worth exactly what it costs you to read it.
Jerry
