I probably will never tow over 5k with mine, and in Oklahoma we don't have many hills so I should be good! Thanks!7-7500k. If you use an app like Torque you, when you start climbing a steep grade, can watch the boost rise, then the engine temp rise, and then the tranny. They never got close to being an issue, but they will rise quickly. Boost = heat and the 2.7 loves to spool those little turbos.
Since part of the OEM tranny cooler runs through the radiator, it picks up the engine heat and transfers it to the tranny...which is why I'm swapping to the massive 6.0 powerstroke tranny cooler and by passing the radiator completly.