The GVWR is based on many components of your truck these include:
Axle, brake size and type, wheel rating, cooling system, frame, engine size and most drive train parts. The manufacturer takes all of these items in consideration when setting the GVWR for a vehicle.
You'll be OK at maximum capacity or a little above but it puts a strain on the truck and affects towing safety (panic stops, quick maneuvers). So you'll need to be more aware and leave plenty of room from other vehicles while on the road.
For 13 years I towed a 5th wheel that was 5,000 lbs over the GVWR of my truck. It was white knuckle driving up and down hills and in traffic. Now I have a truck with 10,000 lbs more capacity than the weight of our 5th wheel. It's a dream to tow with.
