All trucks regardless of classification, payload is the key. Several components together make that number possible. My guess is that engineers have found better ways with newer materials to increase our payload numbers overall improving the truck. I never had a problem in the past either concerning rear axle or wheel issues, however that being said my step father did. He has an early 90 series Chevy 4x4 1/2 ton that he uses in tree work. We have overloaded that truck multiple times with heavy loads from the gooseneck trailer. Lost a rear end or two, but that's after many years of abuse. Never saw an axle break or come off like others have said. I have used 1/2 tons for a while, just wanted extra payload so stepped up to a 3/4 ton. On a funny note, recall the 305 5.0 liter used in gm trucks??? Man those were slower then the 5.7 350 engines....I drove an old c10 with the 305, loaded down, I was afraid to get on the interstate...I had to keep my foot to the floor to maintain any highway speed. I think that truck had 3.42 gears, which of course did not help.....