Agree with waiting and getting a TD DRW when you are ready vice conversion or gaser. I was with a friend this weekend hauling a realatively light 5er and his rig kept overheating on even the smaller hills around Colorado. If you are going to be in any kind of elevation you'll be much happier with a TD! I am always amazed the way we fly up these steep mountain passes around Colorado...the truck acts like its running empty! The other positive I didn't see mentioned was the exhaust brake you have on the diesels now...again in mountainous country that makes a world of difference coming down those 10k+ summits!