Re: F-series rear step bumper fit E-series vans?
Definitely not a direct fit.
I'm in the thick of a retrofit, adapting a heavy plate Ruenel rear bumper scavenged from my '88 F350, cutting off the old, making and relocating new brackets so it will fit onto my '95 Econoline. Most guys won't ever go to that amount of trouble to do this, as it's a lot of heavy steel-type fabrication work.
I have not measured all the variations, but I can say for a fact, that the early F-series trucks, 1980 thru at least 1998, all have narrower frame rails than our vans. depending on how you plan to mount the bumper, this will make a difference. The E-line's frame rails are (outside-to-outside) 42", most 150 and all 250-350 F-series trucks 4-3/4" narrower at 37-1/4". My '88 truck has C-channel ends. I'm not sure of the frame rail ends on later models. My E-line has flat plate flanges welded to the ends of it's frame rails, both front and rear.
For the front, not only are the frame rails narrower on the trucks, but it appears that the overhang, the distance between the wheel opening and bumper face is shorter on the van. Also, our vans look more flat faced, compared to the later trucks that when viewed from above, are less flat, and have more of a larger radiused nose, which will also effect fitment. But you'd have to take a closer look at that.
I hope that helps
1995 E350 7.3 Diesel, 4x4 high roof camper, UJOR 4" lift