By the mid-1950s, Efraín was an accomplished singer in Puerto Rico, but since the island is rather small, he did as many other local performers and emigrated to New York City, as to guarantee a living playing music, given the sizeable Latino population there. When Moncho Leña's orchestra moved to New York City in November 1953, he moved along with them. He went to the extreme of arranging a plena version of "Hava Nagilah" for the Italian and Jewish clubgoers who danced to their music at New York's Palladium Ballroom. He also sang with Joe Cotto and Héctor Pellot. He was featured in the second television music special by the Banco Popular de Puerto Rico in 1960.