...here is the bottom line...
Your truck is not 1,300lb, 5,700lb maybe but not 1,300lb. The lightest ram is around 4,700lb the heaviest ram is 5,700lb.
The difference between our trucks and the 2500 is the springs, shocks, engine and transmission, tires also they used to have different axles but some forums are pointing out that the 2500 and the 1500 share the same axle. And cooling lots of cooling.
One of the main reasons our trucks are rated low on payload is because we are a Class 2a truck.
Truck classification - Wikipedia, the free encyclopedia
Taxes and requirements change the higher up the range you go. Our trucks are designed for light duty and underrated mostly because any higher and we are a 2500 and have to follow those rules and regulations.
So if you want to make a 1500 to do 2500 work you can, but you are no longer under warranty, and the price of modifications you might as well gotten yourself a 2500.
Now do they know you are going to run it hard yes, and they do allow for occasional use of stressing the truck...but under long term stress, your rear coils are going to sag, your transmission is going to need a tune up much sooner than norm, and if you dont up grade your cooling your are going to damage your components over time due to over heating.
Our trucks can take a overload of maybe a 1,000 pounds and shrug it off. Here is why
Payload is curb+passengers - GVCW+towing.
I think our trucks come with 500LB tongue weight limits with our truck (standard hitch?) but that can be added to a payload if not towing just know the bed of the truck is taking that much burden.
and lastly we are not the only trucks with this problem....all 1500s have this problem.
The Tundra Has Ridiculously Low Payload Capacity (???)!!!
How Much Can I Tow/haul With A 1500 Silverado? - 1999-2006 & 2007-2013 Chevrolet Silverado & GMC Sierra 1500 - GM-Trucks.com