The deal worked well until 1967, when the Operating Engineers signed their own collective agreement with heavy contractors, including Armstrong. On May 12, Local 183 decided to go on strike alone. They were motivated by the fact that the contractors offered them a much lower rate of pay than that of the trade unions. Once again, Gallagher was in the hospital, which left Stefanini in the lead. The labour dispute ended on July 10, when the union ratified a new collective agreement. Listen to Stefanini talk about the Armstrong Brothers agreement and the 1967 strike and the legal methods used there. As Zanini later told journalist Catherine Wismer, in the summer of the same year, international plaster and labor executives met in New York, where the former agreed to dismantle Irvines Local 733 and transfer their workers to Local 183. .