M8 GMC was a self-propelled howitzer vehicle of the United States developed during the Second World War.
It was developed on the chassis of the then new Light Tank M5 (General Stuart VI). The test vehicle had the standard M5 turret removed, and replaced with an open topped turret, this vehicle was designated the T47. Armament consisted of a new open topped turret armed with a 75 mm M2 howitzer, later an 75 mm M3 howitzer, which were reworks of the M1A1 pack howitzer. It carried 46 rounds of 75 mm ammunition, types of ammunition carried were; Smoke M89, and H.E. (High Explosive) M48. It featured no coaxial or hull mounted Browning M1919A4 .30-06 machine guns as featured on standard Light Tank M5’s. The only other armament was Browning M2HB .50cal machine gun for local area, and anti-aircraft defence, 400 rounds of .50 cal were stowed onboard for the M2HB. The T47 was ordered into production as the 75 mm Howitzer Motor Carriage M8 in April 1942. Production ran from September 1942, to January 1944. A total of 1,778 vehicles were produced.