I have a 14 Silverado Double Cab 4WD with the 6.2 and the 3.42 axle. The 14 rating was 9500, or 100 lbs. less than a similar configured 5.3. I see now the same configured 2015 6.2 with the 3.42 axle is rated 11,800 or an increase of 2300 lbs. I know the 14 with the 3.42 was not the NHT where the 2015 does. The NHT option increases the ring gear from 9.5 to 9.76; rear axle rating from 3950 to 4100 with no increase in the overall 7200 GVWR. Doesn't seem likely the NHT bits account for much of the 2300 lbs. increase. I believe the 2014 6.2 was way under rated.