Called KMS Parts about their sale April 16-18th 604-522-5593 or 1-800-567-8979
for GM disc brake conversion kit. They have 64-72 A- body , 67-69 F body 68-74 X body $649.95 FRONT ONLY Sale. But in talking to them a 64 impala X frame set front only,which should??? fit a 14 inch ?? every day price $ 749.95
Part # MBM-D5964-PMPV
Hope this helps. I will be getting a set  next month for my 64 c/s