Gotti wasn't promoted to be the head of the Gambinos--he got there by murdering boss Paul Castellano in December 1985. Angelo (Quack-Quack) Ruggiero was a close pal of Gotti's but I don't believe he ever had a captain's tatus. But the time of Gotti's takeover, Ruggiero was ill from the cancer that killed him in 1989, and was under indictment on four serious charges. Gotti's brothers Peter and Gene were the equivalents of crew chiefs at that time. Peter was acting Don after Gotti died. The current boss of the Gambino family, as far as is known, is Jackie (Nose) D'Amico.
Peter became the official boss after John died, and he still holds the title. D'Amico was acting boss before he was indicted.
