BFG LT285/70/R17 E 126R, 3750# at 80 psi.
That's the reading on the tire --- obviously not, stock, however, GM / Chevy replaced the OEM General 265 tires when those tires fails, and got quite squirrely after riding around a few months ... so, at my request, it replaced those (an allowance) and upgraded to the BFG KO 285's at my request ... I had to pay a difference of $720 balanced and installed...
I generally run them at 65 front, 75 rear, altho it says up to 80 psi when loaded. Nice ride for AT's, and so far, getting fairly good mileage -- less than 50 percent worn at 26K miles, all hauling, and a lot of mountain driving. So, I'll be happy with 50-60K miles