That is what I said, the smaller master with power brakes because the ratio is different and the master moves further and the pedal less than with manual brakes, that's why you need a bigger diam master with manual brakes to fill the 10 caliper pistons with fluid, and if you add a booster it wont take very much pedal effort at all to stop the car. But like I said it is a lot of brake for a light car so he shouldn't have a problem.