A crossover nozzle system for transferring molten plastic from an inlet at the center of the stationary platen of an injection machine to the main manifold of the molding chambers of the stack molds of the injection molding machine. The nozzle system has a sprue bar, a sprue bar extension adjustably connected with the sprue bar, the sprue bar extension having a transfer chamber. The nozzle system also has symmetrically placed inlet apertures located in the sprue bar, the apertures are configured to be in fluid communication centrally with the transfer chamber in the sprue bar extension, and a shut-off surface configured to seal the transfer chamber from the inlet apertures.