During the first Colombo war, the Profaci faction had the Gallos pindown to where they could hardly leave their hangout. The reason the Profaci faction did not eliminate the Gallos, was because they knew the NYPD were staked out across from the Gallos. Larry was despite since they could hardly go out and earn much, so he knew someone from the old neighborhood that he was a friend to when they were kids, who had became an officer, and was feeding him information which was passed on to the detectives on the Persicos, Scarpa, a few other hitters who were gunning for the Gallos. This gave the Gallos some breathing room, especially when Joe Profaci died. After Joe Colombo became boss the information stopped coming. It is logical that the informant in the Gallo crew was Larry Gallo, since the Gallos and Colombo made peace and Larry was named Capo right before the informant stopped talking.