[sst5167]

I have made the tow many times. My rig pulls the hills through Colorado ok, but I still prefer taking the 40. What kind of rig are you pulling with. I'd say, if you think you have enough power to get up the hills, and an engine brake to go down the hill, take 70 just for the scenery. But if all you care about is an easy pull, 40 is the way to go hands down.