The M37 HMC was a self-propelled howitzer that was designed as the successor to the M7 Priest. It was based on an lengthened version of the M24 Chaffee's chassis, which had the driver located at the front left and an open top fighting compartment in place of the superstructure and turret. The power train also borrowed elements from the M5 light tank. The M37 was armed with a short-barreled 105-mm M4 howitzer, the same that was used in the close support versions of the M4 Sherman tank. It had a range of just over 11 km, making it effective in the infantry support role especially considering its carrying capacity of 126 rounds. One of the most notable structural features of the M37 was a pulpit mount on the right of the fuselage which was used to equip a .50 cal Browning machine gun, the height of the pulpit allowing it to fire around the main armament at most elevations. This too was a feature borrowed from the M7. Production of the M37 began in early 1945 but entered service too late to see service in World War II. However, it did see combat in the Korean War before being replaced by the M52, though some remained in reserve service until the 1960s. The only export customer was Spain.

The prototype T76 began deveopment in 1943 and entered service as the 105 mm Howitzer Motor Carriage M37 in the second half of 1945. No variants aside from the original model were built.