We are planning a couple of trips this year with our 28' 5500lb travel trailer. 1 trip is going to be about 9 hours(no hills, interstate) and the other about 10 hours, some hills and mountains. Both will be in the fall/winter. All of our trips have been about 2-3 hours up to this point. I am towing with a 2500 5.7 with the 3.73. What's going to be my concerns on a long trip? Would a transmission cooler kit be a good investment? Thanks