As a result of these limitations, New Mexico and Mississippi received a series of rolling changes over the course of late 1942 and into 1943; while at Pearl Harbor in October 1942, they had four of their 5-inch /51 guns removed, along with their directors, to free up space for a pair of quadruple Bofors 40 mm  guns and the shielded tubs for the 1.1-inch guns were converted for use with the 40 mm mounts, though the 1.1-inch guns remained until 1943.