Does the gasser have multiple burners with individual controls? If so, light only one burner and put the ribs on the opposite side of the grill. Try to keep the temp down, but whatever temp it settles in at is good. I prefer 270-ish regardless of the cooker.
If you have wood chips put some in some foil and poke a few holes in the top of the foil with a toothpick and place that near the burner to get some smoke flavor.