Master Cylinder question.

Interesting that the power MC has a smaller bore than the manual. That is probably because the power booster is on standoff brackets with a lever. The lever ratio reduces the pedal force that gets applied to the MC. The smaller bore makes up for that. Remember, they must design it so you can still stop the car if the booster fails. I wonder if the same MC is used for power and manual brakes in my C body, since the pedal acts direct on the MC there. That assumes they ever sold a C body w/o power brakes.