My 2004 4x4 DRW Dodge 3500 weighs 7800 pounds. I find it interesting your new truck is 8740 pounds. I wonder where the additional 940 pounds came from?
My father and I switched from 2004 to 2016/2015 trucks. From what we can gather here is a list of some of the things where the additional weight comes from:
Engine (5.9 to 6.7 means larger block with more beef in the piston walls)
Frame (substantially heavier)
Tires (rim size for dually went from 16->17 and srw 17->18)
transmission (manual to aisin automatic)
front axle (plain solid 4wd to disconnect 4wd for improved mpg combined with stronger tubes for 1,000# added capacity required to carry the heavier engine)
brakes (1" larger diameter and reason for tire size increase)