[twindman]

I had a 2004 Silverado 2500hd diesel. I am pretty sure it's max weight capacity was 9200. The newer ones - 2012 (my new one) could come in either 9200 or 10000, I am pretty sure. So the limit on the 2004 was actually the tires on the rear. My standard LT tires could handle 3040 if memory is correct. x2 = 6080 lb on rear axle. I had a 2980 and I was at 6074 on rear axle. The hitch weight (weighed) was around 2400. BUT the truck limit was 9200 and I exceeded that by around 400.

So yes, you WILL be overweight with your bigger rig.
Now I wasn't too concerned about the 400 over, since on those models the only difference between them and 3500 was an extra spring. So I added air bags. Still was technically overweight tho. I certainly would not run 1000 lb over the truck limit tho.

Strangely the 3500s increase payload by 1000 or 1500 lb and only cost about $1500 more. I goofed and got another 2500 because I thought it would cost $3-5000 more for the 3500.