[old Chevy guy]

You don't have to change the control arm. Just keep the 71 parts there change the spindle. The parts are easier to get and the brakes are supposed to be better. That setup uses the JB8 setup. Not sure how much better but the rotors are thicker if the counts for anything. You can still buy the newer rotors new. I couldn't find anybody that sold that 71 rotor for the bud wheel setup.