A mold assembly for manufacturing concrete blocks and which is adapted for use in a concrete block machine. The mold assembly includes a plurality of liner plates forming at least a first mold cavity, wherein at least a first liner plate is moveable, and a drive assembly. The drive assembly includes a first drive element having a first end and coupled to the first moveable liner plate proximate to a second end, and an actuator assembly. The actuator assembly includes a second drive element selectively coupled to the first drive element proximate to the first end, wherein the actuator assembly is configured to drive the second drive element along a first axis so as to cause at least the second end of the first drive element to move along a second axis and cause the first moveable liner plate to move toward and away from an interior of the first mold cavity.
