A concept for an assault tank from the late 1960s. Placing the engine in the rear recess of the turret made it possible to significantly shorten the hull, which reduced the weight and allowed for enhancing the armor. The tank was supposed to be armed with a British 165 mm L9A1 gun. A license would have been purchased and production set up in the U.S.A. for this purpose. However, due to difficulties in unifying the project with the M48 and M60, which were already in service, the U.S. Army decided to discontinue work on the vehicle.