OK, I think I asked the wrong question. I have bought some 20" 2020 GMC Rims marked 20x8.5Jx31. Neither I nor the person who sold them to me know what they came off of??? I guess the best question would be is are the 2020 20" rim valve holes the same size as the 2019 18" rim valve holes? Man, this is more work than it's worth.......
Dang it.