towing

I have a 2021 Suburban high Country with the 6.2 V8. The difference in towing capacity for this truck vs a similarly equipped Silverado is about 1600 lbs. I am assuming it’s because the rear end in the burb is independent. Are there any upgrades to increase the towing capacity?

I have an 08 5.3L Suburban. I am planning on renting a toy hauler that will be around 7K lbs loaded. I have the factory tow package so it has an aux transmission cooler. I will be towing around 500 miles and will be going through some hills. I know this is pushing toward the top end of the...