Perhaps one should check out the ability of weight carrying/towing between a 3.73 and 4.10 rear end. My 2011 GMC 2500 HD w/3.73 is listed about 4500lbs below same truck with a 4.10. Found this out the hard way. The 3.73 will get a few more mpg, but in the upper loads, you will drop a gear or two on tough hills.