the pedal rod and the booster rod are not one, a diaphram(s) a combo of springs, and plates depending on the booster style "link" the two rods together, but you need to confirm that the booster rod does not have excessive travel inside the master cylinder bore that will result in no/low brake pedal, or repeated pumping to stop the car, no clearance will result in the front and or front and rear brakes dragging/locked without your foot on the pedal