bill the master cylinder does matter. the bore on the back of the master cylinder maters. there are many different types. probably end up needing a 1" bore. the larger the bore the less pedal needed to stop. the problem is if an 1.125" is used when you barly push on the pedal the car will lock up the brakes. you need to match up the bore on the master cylinder to the bore on the piston of the caliper. most common type is 1" bore master cylinder.
