90 miles east of Baton Rouge need tire help

[Coloradobus]

An XL like our 1999 shell, 2001 CC 2 slide has 8.25 inch inner steel\ the rest were Alloy
An XLII, like 2001 shell, 2002 Marathon 1 slide had an 8.25 inch inner steel/the rest were alloy wheel.
An H3-45 1999 shell, 2000 Marathon has 9 inch alloy inner wheel/and the rest are alloy as well


All tires on the above coaches were 315X80X22.5. Prevost would pinch the inner dual onto a 8.25 inch steel wheel. I imagine they still do. Has something to do with keeping the drive axle at 102 inches. We tried to put iinner 9 inch alloy our CCXL and our XLII Marathon and were told NO!! You can't!