We're finalising a disc brake kit for first gen Rivs and before we get a heap of machining under way can anyone help me with this measurement please? From the face of the drum to the end of the hub where the grease cap sits. Our research so far tells us: 1963 Riv = 2-1/8" thanks Paul Benigno 1964 Riv = 2-1/8" thanks Ken at Wheatbelt Auto 1965 Riv = 2-1/4" thanks Ari Blinnikka The weird thing is we have one hub which came off a customer's 63 here in Australia which only measures 1-1/2". It's the perfect size for our disc brake kits. Does any one else have this size on their Riv or does anyone know what other model Buick it could be from? Email me offlist at: email@example.com Thanks again in advance.