Econoline van body mounts

The body mounts on the Econoline are substandard rubber, and the steel bushings have to be ground off.
It is best to use 3/4 in Gr.5 or 8 bolts in place of the spindly @7/16 in. Ones.
The road salt and moisture work their way into the steel bushings and corrode the already spindly bolts.
When you replace the bolts and rubber mounts, the van will have a real tight cornering feel.
Also, provided the radius arm bushing surface is not corroded either. If all the body and front/rear suspension mounts are tight/watertight, the van will handle better than you could believe, without wearing the tires out.
You have to find large diamenter washers, and appropriately sized steel tubing, and make your own steel bushings.
Install the new bushings and rubber mounts with urethane adhesive to keep water out.
The stock rubber mounts are ok, but polyurethane is better.
Why is it important if the '78 or '89 mounts are similar?
Lastly, the frame usually is corroded where the body mounts sit.
This is easily repaired by grinding-out the bad area and welding in an appropriate sized washer.
Econolines can be fixed, but it is not profitable for Ford.
They're sneaky. Vastly more experienced in shennanigans than we can expect.