I found some tires that would be great for the stock 13" rims, they are Dunlop KT122 Bias ATV Tire (25x8x13) even thow they are atv tires they would work great for off road and they range around $65.00 to $75.00. so I hope that they might be some help. I plann on putting them on a gen2 brat with a 6" to 10" lift.
Tyler