They make cupped stainless steel washers just for that problem. I've had a set on my bird for a few years now and daily drive it with no problem. I didn't want to go through the trouble of finding more Pontiac Rallys and then the masking and painting process, so I tried the washers. Been fine since.
I forget where I bought them from but I did a search and lots of places pop up.
Here's one.
https://classicautoparts.com/hub-nut-washer