5x7 / 6x8 in the doors and 6x9 in the rear deck. See more info at the links below... http://www.autoclinix.com/Mercury/Front%20Speakers.html http://www.autoclinix.com/Mercury/Rear%20Speakers.html
6x8
Which ones?
4x6
I believe they are 8" by 9"
Rear Deck Speakers Are 6x9" and the front door panel speakers are 5 1/4"
Should be 4x6. 3x5 is the other size.
front 6x8 back 6x9
6.5 Speakers both in-front and rear
fronts 5" x 7", backs 6" x 9"
The front speakers in a 1997 Mercury Grand Marquis measure 6 inches by 8 inches and they are located in the front door. The rear speakers measure 6 x 9 inches and are located in the rear deck.
6/12 same at the 97
Crutchfield.com states that you can use up to 6"x8" in front doors and the same for rear deck.