You can not put a washer on a dryer. The washer is too heavy for the dryer. There are stacking kits for each manufacturer to put their dryer on their washer.
You can use them if you use self tapping screws to connect them. Before we moved from Las Vegas we did this with our new washer and existing pedestal. The connecting holes are not in the same place, but it works fine. I think it still holds.