I am doing a similar switch on my '64 Belvedere and looked at Wilwood tandem M.C. I was also told that the 1" was for a stiffer pedal and 7/8" was for more of a street car. But they are alot of money. Now I am trying to find out if I can use a M.C. out of a '73 Dart or '79 Diplomat (same M.C.) a lot less money.