I did the 11.75 swap on my 71 Scamp using 73-76 A-body spindles. I used all new NAPA stuff, including non-Chinese rotors, got an E-berg aluminum MC, a Magnum HP adapter and heat shield, and a boneyard prop valve from a 73-76 A-body, boneyard slider caliper adapters from a 78 Cordoba. Cost me about $700 total, and the car stopped on a dime.