Why do people just randomly guess at these things? Making some statement when you don't actually know the answer is less helpful than just remaining silent if you don't know!
The answer is on page 4-52 and 4-53 of the manual. Look at the RPO codes in the glove box to determine which axle you have, look to see if you have the K5L HD cooling equipment or not, and there you go!
Whether you can install aftermarket equipment and achieve the same 'ratings' is another question. I expect GM's answer would be no. Whether you will sustain any damage in real life use is a question that can be answered only by installing the equipment and trying it out.