Thanks for the information. I'm a little nervous but I'll make it. I rarely run over 60 towing and my rig does fine on the flat. I will drive at my comfort level and let the Mario Andretti's go around. I'm more concerned with the down than the up. I have good trailer/truck brakes, I've just never come down a grade with 9k lbs behind me. I have the 4l80E trans not the allison so my rig engine brakes in manual first and second. It will engine brake in third but speed may be a factor as it will hold second to 45 with tow/haul on.