According to Napa Auto the front brake drum for a 1964 C20 uses 11 5/32” x 2 ¾” brakes. Inside diameter is 283.2 mm which equals 11.149606 inches. Maximum discard diameter is 284.73 mm or 11.2098425 inches.

http://www.napaonline.com/Search/De...99645&An=599001+101964+50014+2014028


1960 GMC 1/2-Ton Pickup Truck
In the Gallery
Updates in the DITY Gallery
Now cruising in the Passing Lane