Abstract: A conversion unit is disclosed for converting a mold forming machine from a dry mold material forming process to a moist mold material mold forming process, to form a mold item. The conversion unit comprises mold material injection means having an aperture for injecting the mold material therefrom. The mold material injection means is moved adjacent an aperture in a moldbox of the mold forming machine to inject the mold material into a cavity of the moldbox. The mold material injection means is retracted from the moldbox enabling an aperture sealing means to be rotated between the apertures of the moldbox and the mold material injection means. The mold material injection means is again advanced toward the moldbox to seal the aperture of the moldbox by the aperture sealing means enabling a gas for curing the mold material to enter the mold cavity by gas ports internal the moldbox means.