I promised last week to measure the sizes of both the Ford and the Mazda fuel injector (measured with the oring):
            ENGINE SIDE     FUEL RAIL SIDE
Ford          0.55"                     0.55      
Mazda       0.65 (with the FAT Mazda rubber ring)
                                               0.435

Note that the electrical connector is the same (center spline top/inside and center lower outside).  So, the Ford injector will hook up electrically but the fuel connectors must be different.

Ken Powell