Bnap43

Sierra 6.2. When I accelerate, I am feeling what seems like a few moments of missing or maybe bad fuel flow. Its like the truck jumps a little and is not accelerating smoothly through the gears and up to speed. I have about 85000 miles. Is it time to change plugs and should I add fuel additives? There are no check engine lights. Can anybody help me on where to start looking? Maybe the easy cheap stuff first?