After the Soviet IS-3 heavy tank was unveiled during the Berlin Victory Parade in 1945, the Western Allies were sent into a scramble for a weapon to counter the new threat. Among several of these new projects was the FV4004 Conway, conceived as a stopgap vehicle to carry an extremely powerful 120 mm L1 anti-tank cannon while the Conqueror heavy tank was still under development. Based on the Centurion Mk.3's hull, the Conway's huge 120 mm gun was mounted higher up to avoid damage to the turret ring from recoil after firing, resulting in limited gun elevation and depression. The project would ultimately be cancelled soon after it started in 1951, and the sole prototype of the Conway is currently in storage at the Bovington Tank Museum.

Introduced in Update 1.57 "Battle March", the FV4004 Conway is similar to the related FV4005 in that it focuses primarily on its huge gun. Most of the Conway's characteristics, such as its armour and mobility, are rather subpar, but this is heavily offset by its extraordinarily powerful 120 mm L1A2 anti-tank gun. Its APDS round has enough penetration to even rival modern main battle tanks. Because of this, the Conway is highly specialized in a fire support and sniping role, capable of penetrating any tank it faces, or even those significantly above its BR, like a knife through butter.