[Gegrad]

Yeah, if you are going to head out on a 3500 mile trip this summer I would replace the tires. Carlisle or Sailun seem to be popular choices. You can always sell the old ones to someone just needing tires for a lawn trailer or other small trailer; a set of four should net you $100-150 in return to offset the cost of the new ones. I personally would not head out on a 3500 mile trip with 2 year old Trailer Kings.