They work well on SRW trucks as long as you do not need flotation on sand. The tires are very heavy with stiff sidewalls that do not flex to make a larger footprint, so they will dig rather than float.
225/70R19.5 are more likely the biggest tires your GM will handle with modifications to your front fender liners or suspension. You get the most benefit with 245/70R19.5 tires which typically have 4500-5000 lbs capacity per tire, so you may want to look at a leveling kit, or trimming some of your liner.