It does but not as much as you'd think. The bigger stuff helps with brake torque but its only a percentage with all else being the same.
I went from what you have to 11.75 fronts with the stock calipers, manual 15/16 master cylinder, it was better but incremental
This spring I switched to the Dr Diff 13" Mustang Cobra Fronts and 11.75 Mustang cobra rears. Same master cylinder, and it did stop great, but with a lot of pressure on the pedal.
Once I installed the hydratech, the brakes are basically insanely good, I wasn't used to it and had all 4 locked at 55mph. And I have 275-35-18 Max performance summer tires.