Once upon a time, manufacturers really went out of their ways to make sure that parts from one car wouldn't bolt onto another. Even if it meant changing a spec for no reason at all, it was a matter of principle and brand identity. Now, though, manufacturers often buy parts from outside suppliers, just like anyone else; that can make for some strange bedfellows in the swap department. But stock rims won't exchange.
The Ford Expedition is the SUV equivalent to the F-150; that means it has plenty of options. It's also a step down-market from the Lincoln Navigator, which means that it doesn't get a lot of the flashier appearance and luxury items. The Silverado, on the other hand, has gotten everything that GM could throw at it, which means at least a few sets of snazzy chrome and alloy rims. The 2013-generation Expedition uses a 6-135 bolt pattern, meaning that it has six lug holes that measure 135 mm -- 5.31 inches -- from center to center. The 2013-generation Silverado uses 6-139 wheels, which measure 139 mm or 5.47 inches from center to center. They both use an identical 5.91 inches of backspacing. So, the Silverado's lug holes are 4 mm, 0.13 inch or about 1/8 of an inch further apart than the Ford's. That's very close -- enough so that some aftermarket rims do fit both. However, don't count on the stock wheels from one swapping over to the other. Even if they will physically squeeze over the lugs, the lug nuts will be off-center in the holes. That means less than full contact between the lug nut seats and the wheels, which can lead to lug nuts loosening and falling off, or fracturing of the alloy wheel material. This can happen when non-centered lug nuts put undue point-contact stress on the wheel around the bolt holes.