I’ve never seen a shim crush. A proper one is wedge shaped and made form spring steel. If somebody tried to cut their own out of mild steel, I could see it having issues. A block could do the same thing I suppose.
FWIW Ford sells spring alignment shims. They are used stock on the F650/750 and motorhome chassis. That are not expensive and they do fit the e-series rear springs.
Unfortunately I haven’t been on the water much lately. The Smith River festival was the only one in 2020 that we got in, before things shut down.
The van is doing great though. Only at 496,000 miles though. I’ll post when I hit 500!
2000 E450 dually V10 wagon