Full-Race's Radiator Upgrade can help certainly help with high temperatures when towing. A lower-temp thermostat and a tune doesn't really help all that much, because a thermostat doesn't do anything to improve heat dissipation. Thermostats solely help with lower-end power by opening sooner and won't help mitigate heat-soak. This radiator will help, though you may want to look into an improved transmission cooler, since transmission heat also causes general overheating issues.