C Company, 777th Tank Batallion, Fort Knox 1944 - Chrysler began production of the rare M4A6 (75 done at $64,455 apiece) at Detroit Arsenal, the first being shipped on the 28th of October 1943. The M4A6 reused long chassis, welded hull of the M4A4 but with a brand new large cast front hull. The longer chassis was necessary to accommodate such the new massive multi-fuel air cooled radial engine. The single cast housings and sharp nose of the front hull were others features. The Ordnance Engine RD-1820 9 cylinder air cooled radial 450 hp at 2,000rpm, allowing for a max speed of 30 mph/48 km/h (for short periods). 1000 engines were ordered in total, the remainder bein fitted on comparable M4A4s hulls for extended testing. The M4A6 never saw combat, being used instead at Fort Knox, in the 777th Tank Battalion for extensive testings and were declared Limited Standard on the 3rd of May 1945.