The Armored Gun System was a competition in the 1980s to design a light tank to replace the M551 Sheridan in the 82nd Airborne Division, as well as being expected to replace TOW-equipped HMMWVs in the 2nd Armored Cavalry Regiment (2nd ACR).
Cadillac Gage offered its Stingray light tank with the traditional four-man layout. FMC offered the Close combat Vehicle Light (CCVL) with a three-man configuration. Teledyne offered its Expeditionary tank which had a two-man layout with an experimental unmanned turret. In 1992, FMC's design was selected and type classified as the M8 Armored Gun System.
References
Armored Gun System Wikipedia(Text) CC BY-SA