Here is what I have heard on this to date. It is already done. ASCS Medium tire. You can run it on an 18 and still get stagger according to guys that ran it at Canyon. Size is 105-16-15. Tire durometers at 48 which is slightly softer than a DT3. Has the tread block pattern of an HT2. Hoosier had one mounted up in their booth at PRI on a 17 inch wheel. Will take some experimenting to see which wheel they work best on.

Have heard it will be the USAC, Bloomington, Putnamville and Gas City tire. Haven't heard about the other tracks yet, but they will surely follow suit if this is the case. No info yet if the old tires will have a grace period where they can still be used.

No rules changes on wheels that I have heard of, but the tire may dictate which wheel you need to use to get the best results.