In comparison to the original, the Guntank MPT is almost an entirely different mobile suit. Firstly, the complicated and expensive Core Block System, incorporating an FF-X7 Core Fighter, was deleted from the design all together. However, this also allowed the new model Guntank to rotate at the waist, giving it a much greater firing arc. The armor around the torso was substantially increased, providing extra protection for the driver inside the Guntank's hull. Additionally, the self-contained ammunition magazines were replaced with a large, exposed container on the Guntank's back which would lower into the proper position before firing. This also made it possible for the ammunition to be reloaded mid-combat, essentially allowing the Guntank to continually dump its howitzers at a target. Finally, the limited-capacity missile launchers in the Guntank's arms were replaced with quadruple large-caliber vulcan guns.

A fun little addition, the Guntank can also be equipped with a pair of high-tension crane arms in place of its howitzers to serve as a recovery unit for disabled mobile suits.