Gentlemen: I am considering trying to find a used 2009-2012 GMC (or Chevy) with the Duramax/Allison combination. Please do not tell the better half!! Is there one year to avoid for potential bugs or problems? Anyone know the rear axle ratios available? What kind of fuel mileage can one expect? For the most part it will an errand truck as well as pulling a 24 foot tandem axle trailer. My goal is to be able to haul two small Farmall tractors, 140, Super C, etc. The trailer weighs 2,200 pounds and each tractor would weigh no more than 4,000 pounds or so. For example, the Super C has a planter on the fast hitch and a cultivator on the front. Also considering the Ford and Dodge. For me the Ford goes to the bottom of the list because of its length. Specifications says the crew cab version is 16 inches longer than the GMC with same body style. That means the front of the garage needs to get pushed out, which is not going to happen. Decisions, decisions, decisions!!! Thanks for any and all comments.