2007 GMC Sierra 2500HD Classic SLT 6.0L:
Before my SAS i had: full 1/4" skid plates and rock sliders, 2 batteries, 33" tires steel wheels, steel roof rack, new rear sub (inside original frame rails) frame with 30g blazer fuel tank, steel front (arb) and rear (homemade) bumpers and M8274 winch up front and some accessories. With 2 people and off road gear (100 lbs) truck came out to 8200 lbs.
Updates from then, Corp. 14 bolt/D60 hybrid front axle, coilovers, NV4500 and NP261 (same weight as original np263) swap, and H1 24 bolt wheels and 37" tires (150 a piece at least). I guesstimate weight real close to 9000 lbs. That being said the sprung weight has not changed much.
With eventual cummins 12V swap probably more toward 9500 lbs...
Fullsize 3/4 ton and 1 ton trucks are heavy, add that to the fact that steel is much easier to fab than aluminum and the weight piles on quick.
Cheers,