Consider this, these tires were originally intended to hold up a Jeep and are weight rated as such. Now put another 1000lbs of trailer on top of them and you more than likely have to much sidewall flex due to an overload situation. Which in turn will cause the tires to have MORE, not less rolling resistance. These tires will also have a shorter life and will be more likely to have an overheating issue causing a potential blow out at highway speeds.
I would seriously consider selling these as Jeep replacement tires and get a set of tires intended for towing the weight you will be placing on them.