James,
The spindle size is indeed different on the 322 versus the 317 and the factory wheels with bearings in the hub will not interchange from one to the other.
The FAQ has good info on spindle size versus tractor year/SN at
http://www.wfmachines.com/discus/messages/96042/111892.html?1155072035 and the axles themselves (using different spindles) can be converted from inch to metric or vice versa but it is costly...
What Drew may be referring to on my previous 317 when I had it was a conversion to five lug bolt on wheels which looked like this picture. Those are 18x8.50-10 on the front and 26x12.00-12 on the rear.
Using different hubs on the 322 that also accepted the five lug rims, I now run those tires on one of my 322 tractors (on right in the photo) and also use different bolt on rims in the stock 16x6.50-8 size on the other one that also has the Deere hubs added to the metric spindles.
These metric five lug hubs are expensive to buy from Deere, but give quite a bit of flexibility when it comes to a variety of wheel/tire combinations and the quick swap of wheels without messing with bearings, etc. You can find my thread here
http://www.wfmachines.com/discus/messages/335/393172.html on the 317 project 1 inch spindle conversion using hubs that I got from Surplus Center for under $20 each, but some custom work is required to complete the installation. Army did a similar thing on his 400 loader tractor...
Chuck