[2] The USSR had a history of developing SPGs on the basis of existing medium and heavy tanks, such as the SU-85, SU-100 and SU-152.

Following the development of the IS-3 and IS-4 heavy tanks after World War II, new SPGs were designed (and produced in the case of the Object 704) on their chassis.

However, following decrees #701-270 issued by the Council of Ministers of the USSR, all development and production of heavy tanks weighing more than 50 tons were cancelled, and subsequently, their SPG variants.

Development of the Object 268 began on the 2nd of July, 1952, under orders from the Council of Ministers of the Soviet Union.

[1] #5 received a new engine (the V-12-6, which would be mounted on the T-10M and the Object 268 prototype), slightly altered shape, a new crew member and other minor additions.

[1] Both #4 and #5 were rejected by the GBTU Scientific-Technical Committee and Ministry of Transport and Heavy Machine building, as they required substantial changes to the hull.

[1] By the end of the design process, the vehicle weighed just under 50 tons, and coupled with the powerful V-12-6 engine, could reach a maximum speed of 48km/h.