I don't have any. When I did my 5-lug conversion, the backing plates on the spindles I got were haggard...so I tossed them.
I am sure someone will come on here with the reason they are there, and that you should have them. Afterall, Ford put them there for a reason.....actually ALL auto makers put them there for a reason. But there is no reason you can't run without them.
Did you see if you can simply bend them back a little instead of removing them?