Forest,
A larger master cyl bore will INCREASE the required pedal effort. The original '71 clutch master cyl had a bore of 11/16", so a 3/4" bore master would have INCREASED the pedal effort slightly (~9%).
You might consider installing the clutch pedal effort reduction kit. It does make a difference. Wilkinson lists it for $207 w/o the pedal shaft (item #1), which you don't need.
John
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