Thats the thing, I live in a remote area and have to travel 180 miles of gravel road built on a swamp to leave or come home. I've caught air, not huge air but tires off the ground, in different vehicles multiple times due to the bumps. I had a $5000 suspension system on my 2011 F350 with King shocks, custom coil front springs and Deaver leaf springs. Even with that setup, I still found bumps that would bottom out the truck. So I will not use a spacer that can fail. And I'm 99% sure the 15+ Expeditions have the same lower coilover mount as the 2014+ F150s with two horizontal bolts like you described. And the rears or the same style as the previous years. Here is a picture of the 2014+ F150 mount
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Plus that Expedition that I posted above has rear coilovers. If you look at this picture, you'll see grey coils right beside the rear tire. And if you watch the company's build video, when they show the Icon coilovers, they have grey coils.
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