I have the 6.4 hemi dually 4x4 crew cab long bed. It came with the 3:73 gears and if I had ordered I would have got the available 4:10 gears which are rated to tow more. I pull 10k frequently and it does well. It will rev higher than your diesel but will do it. Fuel mileage will be lower but cost of truck is much lower. The 6.4 is a true medium duty gas engine ( per ram) and I'm sure the possible new bigger hemi will be more powerful. My only suggestion would be to get the DRW instead of SRW. Good luck. I have had zero problems with mine. Will
