Almost every Mini built prior to the dual circuit system uses a .70" bore master cylinder. This kit fits all .70" bore, single line brake masters that use a "cup" seal for the top seal. The original size in the '59-'64 Mini was .75" but as most of these cylinders have been replaced with the .70" size it is best to check the very early models. See GRK1006 for the "ring" seal repair kit. 88G8689 is the kit for GMC171 and GMC172.