490 v8 motor
A 460 385 series engine was an option in 1969. In 1968 the FE big blocks were an option so I would say this swap is do-able.
Never heard of a 490 in the Ford/Mercury line. Do you mean a 390? Those were very common back then. If so then yes it will fit with the right mounts. Had an LTD with a 390 in it man that car would move.
Search Mercury Grand Marquis Questions
Mercury Grand Marquis Experts
Related Models For Sale