The rear bumper on Escalades is actually a bumper cover. Here's a link to LMC that shows the Denali rear bumper cover (I think they're the same as the Escalades).
http://www.lmctruck.com/icatalog/csd/full.aspx?Page=22
The only problem I see with it is that the Escalades have cladding down the sides, and that makes them just a little bit wider and also extends the body down lower than a normal Tahoe. The bumper cover is made to line up with this cladding, so without it, I think the bumper would stick out to the sides and also look like it hangs too low. Maybe it would look fine, though. I'm not really sure. Would you be able to test fit the cover before you bought it? I don't think I've ever seen a normal truck with the escalade rear bumper before.
Look at the cladding along the side (especially right under the gas tank), and see how it lines up with the bumper.
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