Our 2002 E450 dash was also 1.5-DIN. I got a 1.0-DIN AM/FM/HD/CD/USB with remote control from Amazon for about $100. Daughter's Explorer about that age was 2.0-DIN and those super-fancy stereo's would fit. I guess Ford (and it would seem GM) thought a mere van owner wouldn't want such luxury.
Here's one in
in JVC Brand from Amazon, less than I paid for our Dual brand a few years ago. And its picture:
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. I used the install kit (metal "can" that came with the new unit, and wired it color-to-color like the original. Ours was a Panasonic. Since it was also 1.0-DIN, an 0.5-DIN filler was already there. It forms a little tray below the radio. I made the wiring up first with wire nuts. Tested and found it worked exactly as it should. Went back with Red Butt Connectors. A very easy project.