Second the motion on the exhaust brake.

If you are going to pull in the mountains with a heavy load, your brakes will not hold up. While pulling a 30 foot gooseneck with two Jeeps on it in Colorado when coming down a long pass, being as careful as I could be, my 2500 truck brakes heated up and all the warning whistles and lights came on. Luckily, I was able to pull off the highway until they cooled down. When I got home, I had an exhaust brake installed.

I now drive a 3500.