It's been a long time since I have installed a stacked neptune washer/dryer combo.
From what I recall the dryer basically sat on top the washer and there were to metal brackets that connected the two from the rear of the unit.
I also recall installing some neptune unit that come from the factory as one unit and the washer and dryer could not be separated so it had to be moved as one piece.
I tried to find a copy of your owners manual at this URL to see what it said about installing it, but did not have any luck.
www.maytag.com/manualsIf you look at the back of the unit and don't see two mounting brackets connecting the dryer to the washer you may have a model that has to be moved as one unit.