Is there an ideal level for air to enter a firebox? By that I mean entering beneath the splits, same level as the splits or does it even matter? My firebox has two openings at 9 and 3 o clock but the floor of the firebox sits approx. 3 inches deeper. Just wondering if I were to elevate the grate that the splits sit on that it might provide easier starts. I have a T design smoker from Johnson smokers.