As the Earth Federal Forces concentrated their manufacturing efforts on the production of their new mass-produced RGM-79 GM units during the latter months of the One Year War, those mobile suits already fielded had to make do with what few materials were available. Since the RX-79[G] Gundams were themselves built using spare parts, virtually no replacement parts were available for repairing damaged units, and field engineers had to literally rebuild mobile suits with whatever they could find. One example of the latter was the Ez8 used by 2nd Lieutenant Shiro Amada, commander of the Kojima battalion's 08th MS Team. .

After Shiro's RX-79[G] Gundam was heavily damaged early in November, UC 0079, the Kojima battalion's engineers rebuilt it using custom components. The RX-79[G]Ez-8 Gundam Ez8 (short for "Extra zero-8") retained the same beam sabers in the legs, as well as the standard RX-79[G] hand armaments. However, its other fixed weapons were changed out, with a pair of 35 mm machineguns mounted in the head and a turret-mounted 12.7 mm anti-personnel machinegun in the chest. The Ez8's armor plating and placement was improved overall, and the traditional Gundam "V-fin" on the head was replaced with a sturdier communications antenna. The Ez8 did retain the backpack equipment rack from the standard RX-79[G], allowing it to keep its ability to mount parachute packs or other field equipment options.

Source: Gundamproject.com, Kit Manual