This moved to the updated M5 chassis, differing from the M3 mostly in its engine, while introducing a new fighting compartment with a well-sloped front that provided more room and much better protection.

A further revision moved the gun to one side to free up room and change the balance, which was successful enough to consider production on surplus M3 chassis.

The T47 was also developed on the basis of the M5 chassis, but replaced the fixed fighting compartment with a new manually-turned turret mounting the same gun.

In the M8, the hatches were replaced with smaller hinged plates on the front of the glacis that could be opened by rotating them upward or lowered to "button up".

In early 1944, production was phased out in favor of the M4 or M4A3 armed with the M101 howitzer, having better protection, firepower and mobility (albeit not as fast).

The plate sloped at 50 degrees for a short distance before it met the hull roof, which was uniformly 0.5 in (13 mm) thick, and flat.

Unlike the standard M5 light tank, the M8 featured no hull-mounted or coaxial Browning M1919A4 .30 caliber machine gun.

A Browning M2HB .50 caliber machine gun with 400 rounds was mounted on the right rear corner of the turret for local defense and anti-aircraft purposes.

For self-defense, the vehicle driver was provided with a Thompson submachine gun, while the other three crew members were issued M1 carbines.

[11] The 75 mm howitzer motor carriage M8 was assigned to the Assault Gun Troops of Cavalry Reconnaissance Squadrons in order to give them close support against enemy fortified positions.