Run with the real trucks. Not the one that's running away and headed for the sand trap lol! Slow and easy and enjoy the views.
Lynnmor is right. We're not driving OTR tractor trailers. Use a lower gear, drive slower, whatever it takes to keep from using the brakes to excess. If your '08 Ram doesn't downshift with a tap of the brakes in tow/haul mode, you might need to downshift manually to maintain your desired speed without having to continually hold the brakes. If you run in 2nd gear up at 4k rpm, you'll likey want to run in 2nd gear down at the same speed or slower. Truckers have likely run the passes many times and have experience with a lot more weight than we're dealing with. Run the speeds they run and you should be fine.