It's not enough to know that it rubs, the important thing is to know WHERE it is rubbing.
Personally I would expect it to rub in a number of locations, adding spacers may help in one area and simultaneously aggravate the situation in another, also, be aware that as the rear axle moves away from the body, it moves forward, bringing the rear tires closer to the front of the arch.
A 245/70R16 tire is 2.4" larger than stock - I would expect the front tires to rub on the frame and also the plastic inner arch liner when on full lock - in a left turn the left tire will rub on the frame behind the wheel, and the right on the arch liner in front of the wheel, and vice versa for a right turn, there may also be some fouling on the seam at the back of the arch - if this happens, adding spacers will fix the rubbing on the frame, whilst aggravating the rub at the other two spots.
In the rear the tires are going to be very close to the front edge of the arch with the vehicle at rest, and under compression they will move back, very close to the rear of the arch - possibly close enough to foul and spacers are not going to fix that - IF it happens, trimming (or smaller tires) are the only options, be warned there is not a lot of trimming that can be done at the front of the arch.
One last thing - larger tires are going to affect your gearing - it's going to be very difficult, if not impossible, to find gears for an XL-7.
These are just my thoughts, based on what I have seen & experienced with my own car, take them for what they're worth and bear in mind, I drive a GV, not an XL-7, I have less lift than you do, and run smaller tires than you are planning to.
