An injection molding machine includes a machine base extending along a horizontal machine axis; a stationary platen fixed to the base; a moving platen supported by the base; a center section supported by the base axially intermediate the stationary and moving platens; at least one mold stroke actuator for translating the moving platen and the center section along the machine axis between a mold-open position and a mold-closed position; a two-stage first injection unit supported by the base behind the stationary platen for injecting a first resin through the stationary platen; and a two-stage second injection unit supported by the base behind the moving platen for injecting a second resin through the moving platen. The second injection unit is translatable along the machine axis to accommodate translation of the moving platen during movement between the mold-open and mold-closed positions.