I also have a 2000 790, set up just like yours. If you adjust the turnbuckles to the point where there is very little sway (an 1", to protect the turnbuckles from getting stretched), the lift arms will not interfere with the tires. They get close, but they will clear. As suggested, you can also swap the implement link pins to the inside, which will move the lift arms in quite a bit. From there, you can switch the rims around, or get wheel spacers.
This is an issue with lots of compact and sub compact Deere tractors. I build telescoping stabilizers for a living, and see interference issues often. It is common for a new owner not to know about adjusting the turnbuckles, or that the turnbuckles are damaged or corroded to the point that they can't be adjusted. Their role is to keep the implement stable and to keep the arms away from the tires.
If the turnbuckles won't turn, they can be replaced. New turnbuckles are inexpensive, and adaptable. On my tractor, I built a set of telescoping stabilizers. However, they aren't a bolt on kit- the 790 required some alterations for them to function well.