Carlo Gambino died in 1976, six years after the RICO law went into effect. Although RICO made it much easier to prosecute Mob bosses, evidence was still needed to convict them. The charges that were brought against the Mob bosses in the famous "Commission" case in 1985 were based on wiretaps and other electronic surveillance that law enforcement had accumulated against them. They were careless and stupid. Gambino was careful and smart.

I'm guessing that if he had lived into the Eighties, he would not have blabbed and made the dumb mistakes that the other Dons made. Example: Paul Castellano was indicted because the FBI managed to put a microphone into his dining room, where he met with subordinates, and discussed all family business in clear (and incriminating) language. But if they'd managed to bug Carlo Gambino's home, they wouldn't have gotten anything because Gambino spoke in a code with his people--he always assumed his place was bugged (even if it wasn't), and took that precaution.