A connector support assembly is configured to securely retain a mating connector during an assembling process of an electrical connector. The connector support assembly includes a universal base, and a plurality of inserts configured to be interchangeably retained by the universal base. Each of the inserts includes a base connection interface that is configured to be retained by the universal base, and at least one shell connection interface. The shell connection interface(s) of at least two of the inserts are configured to retain different sized shells of different mating connectors.