Larger tires are also heavier for the same model.
LT tires are heavier than P tires of the same model.
Heavier tires costs performance, acceleration, braking, and handling, much more so than say 40 pounds of dead weight in the truck bed.
If you can find a similar weight quality LT tire in your stock size, go for it. But I'd stick with what works, a p-tire in stock size. But a good one. It's the only thing connecting the vehicle to the road and the single largest impact in vehicle handling under all driving conditions for any given vehicle.
