Yes, to a certain extant her armament was different, though superficially looked the same.
The Iowas had the 16-inch/50 caliber Mark 7 which GlobalSecurity describes it this way: "The IOWA class are the only battleships to mount this weapon which is a considerable improvement over the 16in/45cal guns mounted in the North Carolina and South Dakota classes."
The secondary armament on the Iowas and the Alabama was identical in type and number specifically 20 of the Mk 28 - 5-inch / 38 caliber guns mounted 2 guns X 10 mounts. The 5-inch/38 was used on virtually all US warships of destroyer size and larger. (Alabama's sistership South Dakota was outfitted as a flagship and so carried only 16 5-inchers.)
The number of 20mm and 40mm AA guns carried by each ship varied even amongst ships in the same class, but generally speaking, an Iowa-class carried more of both owing to it's larger size.