A blow molding machine assembly configured to be mounted to a blow molding machine to move a mold base configured to form a container base. The blow molding machine assembly includes an over-stroke cylinder and a counter-stretch rod. The over-stroke cylinder is configured to move the mold base between an extended base position and a retracted base position. The counter-stretch rod is movable between a retracted rod position in which the counter-stretch rod does not extend out from within the mold base, and an extended rod position in which the counter-stretch rod extends out from within the mold base.