I used my craftsman set to remove 12 class 12.9 (grade 9) socket head cap screws (perfectly round from the factory) that held on Jetta half shafts (very limited access) because I didn't want to buy a triple square bit. They were only like 50 ft-lbs, but had thread locker on them. Bolt-outs worked perfectly, but I had to use a small one and really hammer it on there.
If a hex head rounds off with a good socket on it correctly, I'd suspect that the thread diameter would snap anyway. At least that's what I've seen on GMT 400 unit bearings in Alaska.
BTW, suburbans have 2500 knuckles/wheel bearings. They didn't make a 3500 suburban.
I'd just get a whole knuckle assembly from the junkyard and do the bal l joints while you're there. The uppers are terrible on the gmt400s anyway because the seal doesn't work properly.