15/16 or 1 1/32

master cyl. changing over the dart to bbp, front disc and rea drum. got a new m/c from a 76 aspen(1 1/32 piston). how much difference in the pedal feel between the 15/16 m/c and 1 1/32 m/c? rear brakes will be 10 or 11 x 2 1/2.