I vote rear. Two problems I see with putting it on the front:
If you have to swerve suddenly id be afraid of it rolling off the rim.
If you slam on the brakes I think it will pull hard to the side.
Also, since we have open diffs I don't believe the difference in circumference will lead to much additional heat in the rear.
Sent from my SAMSUNG-SGH-I747 using Tapatalk