Altough it is mentioned in American gangster that Armand Assante's character is the boss of the Lucchese family, he is completely fictitious. He is portrayed as a sort of top boss in the New York underworld, while Tramunti wasn't. For that reason he is more likely based on Carlo Gambino.
Creative license, no doubt. Tramunti never approached a "Boss of Bosses" type of power. But the fact remains that the only Lucchese heavyweight convicted relative to the "French Connection" case was Tramunti. The character is more than likely a composite of several guys, not even necessarily bosses. But who knows for sure?
Lucas' account should be taken with a grain of salt, though. Like any other criminal who got his story published or made into a film (Henry Hill, et al.), there's going to be an expected amount of self-aggrandizement. "American Gangster" was a pretty good film, though. If "The Departed" didn't clean up just a year before, it may have even gotten some Oscar recognition. But they weren't going to vote "gangster" two years in a row.
