Go to an online tire store like Tire Rack, and enter in your vehicle...it will give you the OEM tire size...I’d lean towards that size.
Something not a lot of people consider in tire sizes on trucks...
Fords and Dodges can take oversized stuff. You can go nuts with the tires. Chevy though, not so much.
It’s all about the offset in the design. The Chevy axle calculates wheel offsets on the “Doesn’t look cool” side to improve it’s overall weight capacity. A wheel with less offset (More pokey-outey look-at-me) actually reduces the maximum axle capacity because.. the wheel will actually warp.
Chevys aren’t that accomodating with changing tire and wheel dimensions. They need to stay near the factory size and offset. If you don’t, it will affect the performance and satisfaction you’ll get out of it.
Fords and Dodges are more accomodating.