Hey Grigg,
Iam looking at a set of 22.5 alcoas part no 873607. they are a 7.5 x 22.5. was going to get a set of adaptors made. My initial investigations found a 225/70/22.5 which is perfect to replace the 7.00x 20 on the front and 255/70/22.5 on the rear which would be a good replacement for the 7.50x20 rears. the 255/70/22.5 rears are no problem but I went searching for the 225/70/22.5 for the front and now I cant seem to find any suppliers. I was under the impression it was a tyre that was used a lot in RVs. Now iam not sure if they ever existed