I have the receipts for thousands of dollars for the cost of replacing a blown rear end because I overloaded the rear axle on my 01 1500 Burb. Happened twice, while on separate vacations.
The rear axle is the weak link of the powertrain and suspension of a 1500 GMT800 Suburban. Changing gears, brakes, springs, or shocks doesn't change the fact that it's a weak semi-floater that overheats easily. And none of those mods changes the fact that the rear axle is rated to 4,000 lbs and the GVWR is 7,200 lbs.
There's an easy way to fix the problem. Sell the truck and get a 2500 Suburban. That's what I did.
Oh, and BTW, upgrading to a 2500 only adds ~500-600 lbs of payload, but you also get a full-floater rear axle rated to 5500 lbs.
