For 1981, a 4.2L V8 was added as the standard engine on base-trim versions of the Marquis, with the 5.0L engine offered on four-door versions of the Marquis Brougham and Grand Marquis. In 1982, the 5.8L V8 was dropped from the Marquis line in the U.S but continued to be offered in Canada. In 1979-81 the 351M was offered in Canadian spec cars with the optional heavy-duty towing package only paired to the C6 transmission. When introduced for 1979, both V8 engines were paired with a 3-speed SelectShift automatic. For 1980, the Marquis received the 4-speed AOD overdrive automatic transmission as standard equipment with the 4.2L V8 and was offered as an option with the 5.0L and 5.8L engines. For 1982, the AOD became the sole transmission for all three engines.