I had the c10 headmans on my 61. They worked ok after I hammered one tube, notched the bell housing cross member (which you already cut out or your auto trans would not fit) and relocated the brake lines for driver front. If I were to do it again, I would have used the 327 vette ramhorns like mentioned above. Thought I would chime in, just incase you had any remaining doubts about the ramhorns.
