I have purchased several sets of 19. 5" steel wheels for dually's that are 6. 75" wide and offer the correct offset to mount either the 225 R70/19. 5" - 245R70/19. 5" tire... don't hold me on the aspect ratio... but the same rubber used on our F550 and new 08 5500...
We import those wheels in powder coated black... .
The wheels are load rated for the listed tires, and are hub centric. .
If you mount the 225, this tire is so close to the height of the stock 16" or 17" no other changes are needed... .
I have sets on my 04, 04. 5 and 05... . we run a new tire on the front with the UPS Bandag style cap on the rear... and usually see over a 100K miles per set of tires... The F550 now has over 500K miles on the chassis.....
I'm guessing that I'm at least 3-4 months out for more of them... . if you have any specific questions either post it here or write me...